To prove whether IL-15 directly affects ILC1s, the authors cultured ILC1s from RCC tumors in the presence of IL-15/IL-15Rα complexes: Here, IL-15/IL-15Rα complexes increased granzyme A and CD56 expression, proliferation, as well as cytotoxicity of ILC1s, indicating that IL-15 is a crucial regulator of ILC1-mediated cancer immunosurveillance. Here, IL15 is linked to renal cell carcinoma.