Paul Christou, the lead author of Arjo et al. [13], demanded that our paper be retracted and insulted us personally. He claimed first in a letter addressed to the editor-in-chief that the publication of our study ‘does not meet minimal acceptable standards of scientific rigor’ and ‘will damage an entire scientific discipline due to flawed conclusion’ (personal communication). Then, he attacked us in an article published in the journal Transgenic Research on 20 December 2012 [13]. The quantity of insults and defamations in this paper, authorized and co-authored by the editor-in-chief in a supposedly serious journal, is excessive. They include: ‘abject failure to treat the experimental animals in a humane manner’, ‘inability to formulate a valid hypothesis’, ‘media fanfare’, ‘fraudulent or knowingly inaccurate statements’, ‘unethical behavior’, ‘transparent attempt to discredit regulatory agencies’, ‘ammunition for extremists’, ‘flawed science’, ‘disingenuous or inept’, and ‘unjustified waste of animals’ (while at the same time asking for more animals in the groups). Christou and co-authors suggest that by practising ‘flawed science’, we are working against ‘progress towards a better quality of life’ and in fact are ‘actively working to make life worse’. We were not invited to reply. This behaviour can be explained, though not justified, by the undisclosed conflicts of interests.

Christou is not only the editor-in-chief of Transgenic Research, the journal in which he published his article, but is also linked to Monsanto [18]. He is named as the inventor on several patents on GM crop technology, for most of which Monsanto owns the property rights. These include patents on the plant transformation process [19] used to make glyphosate-tolerant transgenic corn plants [20]. He worked as a researcher at Agracetus Inc. (later acquired by Monsanto) for 12 years. Then, from 1994 to 2001, Christou worked at the John Innes Centre in the UK [18], which is heavily invested in GM crop technology [21]. He thus has no mammalian toxicology background. However, in his published article, Christou only gave as his affiliation his publicly funded position at a research institute. Christou’s failure to declare his current interests - his inventor status on patents concerning the company that developed the products we tested - could be considered grounds for retraction of a paper in a scientific journal, according to ethical guidelines for scientific publishing [22].

The Arjo et al. article was co-authored by Wayne Parrott, an active member of the Biotechnology Committee at the International Life Sciences Institute (ILSI) [23]. ILSI is funded by multinational food, agribusiness, and biotechnology companies, including Monsanto and Syngenta [24]. ILSI has proved highly controversial in North America and Europe due to its influence on risk assessment methodologies for chemicals, pesticides, and GM foods [25–27]. Wayne Parrott also has an inventor status in patents on materials and methods for selecting transgenic organisms [28] and transformation vector systems [29].

In addition, Christou and his co-authors made numerous mistakes, false and unsubstantiated assertions, and misrepresentations of our data. The title of Arjo et al.’s paper includes defamation and a misrepresentation of our research, implying that it is ‘pseudoscience’ and alleging that it claimed Roundup Ready maize and Roundup herbicide caused ‘cancer’ in rats - a claim we never made. We did not even use the word ‘cancer’ in our paper although this argument was reiterated in the final letter of the editor-in-chief of FCT when explaining his decision to retract our paper [30]. Tumors do not always lead to cancer, even if they can be more deleterious in a shorter time because of their size or body position, by hurting internal functions.

Arjo et al.’s paper begins with a false assertion that is not evidenced in the paper or in the cited source: ‘It started with a press conference in which journalists agreed not to engage in fact-checking’. The authors made other false assertions about our study, for example, alleging that ‘the water consumption was not measured’. In fact, we measured both the water and food consumption, and the stability of the Roundup solution over time. This was indicated in the paper, in which we explained that all the data cannot be shown in one paper and that we concentrated on the most important data; these parameters were only part of a routine survey. They also falsified the reporting of the data, compiling the mortality data only at the end of the experiment and ignoring the originality and the major findings of the differential chronological effects between treated rats and controls, which we established by measuring tumor size twice a week over 2 years. Moreover, we respected legal requirements and ethical norms relating to animal experiments, and Arjo et al. present no evidence of the contrary, so their allegation of inhumane treatment of the rats is without substance.

Importantly, we had already answered many of the criticisms of our paper made by Arjo et al. in a paper that was published before that of Arjo et al. [12]. Their publication was received on 20 December 2012, when our paper was published on 9 November 2012. Our published answers were simply ignored.

Christou was not alone in failing to declare conflicts of interest in his criticism of our paper. Since we underlined that 75% of the comments addressed to FCT within a week after our study was published came from plant biologists, it was discovered that several had developed patents on GMOs. Some authors were employees of Monsanto Company, which owns NK603 GM maize and sells Roundup herbicide [4, 11]. Other more recent papers, published by plant biologists and/or affiliates of the industry-funded group ILSI [15, 16], repeated the arguments. The author of a separate article criticizing our study expressed concern that our results could damage public opinion about GM crops [14] - a sentiment that gives precedence to economic interests over public health. An article in Forbes magazine even alleged, without presenting any evidence, that we had committed fraud [31]. Surprisingly, even Monsanto authors [11] declared that they had ‘no conflicts of interest’ in their first draft published online on FCT website. Investigative reports [32, 33] evidenced that many authors of these opinions had failed to disclose their conflicts of interest, including Henry Miller, Mark Tester, Chris Leaver, Bruce Chassy, Martina Newell-McGloughlin, Andrew Cockburn, L. Val Giddings, Sivramiah Shantharam, Lucia de Souza, Erio Barale-Thomas, and Marc Fellous. The undisclosed conflicts of interest included links with biotechnology companies that develop GMOs and with industry-backed lobbying organizations.

All of this has huge implications for public health. We observed an intense lobbying in parliaments, as well as proofs of conflicts of interests for persons involved in the regulatory decisions for the commercialization of these products [26]. A series of high-profile conflict-of-interest revelations (not restricted to GMOs and pesticides) led to the resignations of leading administrators involved in decisions affecting the assessment of these products, including the European Commissioner John Dalli [34] and the former chair of the European Food Safety Authority’s (EFSA) management board Diana Banati [35]. In February of 2013, a strange occurrence following the publication of our paper raised questions about the connections of industry to scientific publishing, described below.