This year marks the 40th anniversary of a landmark paper describing the discovery of tumour necrosis factor (TNF), a pivotal cell-signalling protein in inflammatory disease known as a cytokine (E. A. Carswell et al. Proc. Natl Acad. Sci. USA 72, 3666–3670; 1975). More than 122,000 publications on TNF followed — including reports that led to an important drug for treating arthritis, etanercept.

TNF's eponymous anti-cancer effects were unwittingly exploited by William Coley and colleagues as long ago as the end of the nineteenth century, after the likely induction of TNF by a mix of bacterial toxins (see B. Wiemann and C. O. Starnes Pharmacol. Ther. 64, 529–564; 1994).

And many centuries earlier, in 1322, a Parisian midwife called Jacoba Felicie successfully burned the tissue around tumours to make them regress. We now know that burns cause inflammation, which activates TNF. As a woman, she was not permitted to qualify as a doctor, so she was put on trial for practising medicine and banished from Paris.