Factors other than citation doping could have contributed to the recent rise in the number of Italians among the 100,000 most highly cited scientists (see Nature http://doi.org/dcgj; 2019).

Of the 100,000 most highly cited scientists in the database compiled by John Ioannidis et al. (PLoS Biol. http://doi.org/gf6ckr; 2019), including some 2,000 Italians, we found that the proportion using self-citation to boost their research impact was probably only 2% (see P. D’Antuono and M. Ciavarella Preprint at https://arxiv.org/abs/1910.02948v1; 2019). The practice seems to be more common among early-career scientists who are otherwise less frequently cited.

ANVUR, the Italian agency for research evaluation (go.nature.com/2kwu5jj), should in our view exclude self-citations from future evaluations, to avoid this ‘noise’.

We consider that the jump in the number of Italians in the 100,000 most highly cited researchers is a symptom of the overall health of the Italian research system. It underscores the positive effect of introducing ANVUR in 2006.