Moreover, we show that IL-15 complexes primarily localize to the paracortical (black arrows) and, to a lesser extent, the cortical regions (white arrows) of the tumor-draining lymph nodes, and anti-PD-1 mAb is detected in the tumor-draining lymph nodes, where they colocalize in primary and secondary follicles (gray arrows). The gene discussed is IL15; the disease is neoplasm.