This raises important translational considerations: while IL-2– and IL-15–based immunotherapies are feasible in principle, their application in aged individuals — particularly females — may require careful dose titration, personalized cytokine delivery strategies (e.g., tumour-targeted IL-15 prodrugs; [7], and potentially, the co-administration of immune checkpoint inhibitors (e.g., PD-1) to prevent immune-mediated pathology [61]. This evidence concerns the gene PDCD1 and neoplasm.