Supernatants from pancreatic cancer cells had significantly higher levels of VIP when compared to melanoma and breast cancer cells (Table 1).Treatment of immune competent mice bearing melanoma or pancreatic cancer cells with the combination of VIPhyb and anti-PD-1 (combination group) produced complete and durable regression of tumors in 20% of the mice in the melanoma model (Figure 1) and increased median survival in the pancreatic cancer model (Figure 2). Here, PDCD1 is linked to melanoma.