Conversely, although the objective response rate of the anti-PD-1 ICI, pembrolizumab, in patients with previously treated advanced noncolorectal dMMR/MSI-H cancers has been reported as 34.3% (80 of 233 patients), the response rate in PC was only 18.2% (4 of 22 patients) in the Phase II KEYNOTE-158 study (34). Here, PDCD1 is linked to cancer.