The newest Cell sister journal, Cell Systems, just launched an interesting new format called Math | Bio. In an editorial announcing the new format, Quincey Justman explains that by creating this new format the editors hope to encourage papers like John Hopfield’s 1974 work on kinetic proofreading — a paper that discussed an idea about how biology could work, without attempting in any way to prove that biology did work that way. Let’s hope it’s successful! There are many nice things about this format. What I like most is that it opens a channel between people who have theoretical ideas but no way to test them and people who may have relevant experimental results but are puzzled about how to interpret them. Also, if biology is more theoretical than physics — as Jeremy Gunawardena has argued — we need more and better channels to get the theory out there.

And it’s also nice, of course, that the inaugural Math | Bio paper is from our Department. In it, Yoni Savir, Ben Tu from UT Southwestern, and Mike Springer describe a possible design for a biological linear rectifier. A linear rectifier produces an output that is linear relative to input above a threshold, and over a wide range of input values. Savir et al. argue that such a device could be useful in many settings in biology, including nutrient regulation of growth rate and gene expression; and they show that a relatively simple motif involving competitive inhibition could behave in this way.

So, is anyone out there scratching their head over an output that seems weirdly linear and just won’t saturate? You could be lucky: it might not be an artefact after all, but the first example of an exciting new form of biological signal processing. Check it out.