To test whether treatment with the combination of VIP-R antagonists with anti-PD1 antibodies enhanced anti-cancer immunological memory more than treatment with anti-PD1 antibodies alone, we rechallenged tumor-free mice (without detectable tumor by palpation or BLI) with a second inoculation of KPC.Luc 80-100 days after initial treatment with either anti-PD1 alone (n = 6) or the combination of anti-PD1 antibody with either ANT008 (n = 5) or ANT308 (n = 3) (Fig. 5f). Here, VIPR1 is linked to neoplasm.