IL15 and neoplasm: For pancreatic cancer, which has such an immunosuppressive tumor microenvironment, bispecific antibodies with combinations of checkpoint blockade (PD-L1/CD3) or targeting macrophage reprogramming (CD47/SIRPα) are introduced to increase anti-tumor immunity, whereas trispecific constructs augment T cell persistence and infiltration through immune-stimulatory cytokines like IL-15 [62,63,64,65].