Recently, a prospective phase II clinical trial (NCT04165772) was performed in which dostarlimab, an anti-PD-1 mAb, was applied every 3 weeks for 6 months in 12 patients with mismatch-repair-deficient stage II or III rectal adenocarcinoma following standard chemoradiotherapy and surgery. The gene discussed is PDCD1; the disease is rectum adenocarcinoma.