Preliminary data from clinical trials (NCT04126733, NCT03406871, NCT02870920, NCT05608044) treating microsatellite stable CRC patients with a combination of anti-PD-1 antibodies or PD-1-targeting drugs with either anti-CTLA4 antibody or kinase inhibitors (regorafenib) have suggested beneficial response rates between 7% and 36%.65 Here, PDCD1 is linked to colorectal carcinoma.