IL21 and skin neoplasm: To identify potential drivers of AREG production in NK cells within skin tumors, we tested 14 stimulation conditions, including inflammatory cytokines (IL‐2, IL‐12, IL‐15, IL‐18, IL‐21), activating receptor ligands (4‐1BBL, MICA), activating antibodies (anti‐CD2, anti‐NKp46), and metabolic regulators (IGF‐I, IGF‐II, insulin, transferrin), both individually and in combination.