PDCD1 and breast neoplasm: We also treated aggressive triple negative 4T1 breast tumors with a single IP injection of pHLIP-STINGa (100 μM 300 μl) when tumors reached a volume of ~100 mm3 (designated as day 1) or 3 IP injections on days 4, 9 and 14 of an anti-PD-1 antibody (250 μg/injection) or a combination of pHLIP-STINGa with the PD-1 antibody series.