IL15 and infection: For example, IL1-β (gene IL1B) and IL23, which were markedly induced by Mtb in our infection model (Figure S4 in Supplementary Material), are known to induce group 3 ILC (ILC3) (16, 17); IL15 among others activates ILC1 cells, and IL1-β, thymic stromal lymphopoietin (TSLP) and IL33 are prominent activators of ILC2 cells (17–20).