IL15 and cancer: Recent clinical progress includes the FDA approval of Nogapendekin alfa inbakicept (N-803), the first IL-15-based immunotherapy approved for cancer treatment, alongside the advancement of other IL-15 superagonists into Phase II trials and growing evidence that IL-15 can enhance the efficacy of immune checkpoint blockade and engineered adoptive cell therapies such as CAR-T cells, CAR-NK cells, <i>γδ</i> T cells, and invariant NKT cells.