To delve into the properties of NK cells, Cosan et al.33classified them into different types depending on cytokine secretion and found an increase in IFN‐γ+ NK cells in patients with Behcet's disease compared to controls, offset by a decrease in IL‐5+CD16+, IL‐17+CD16+ and IL‐10‐secreting regulatory NK subsets. The gene discussed is IL17A; the disease is Behcet disease.