Although the earlier Checkmate-142 study suggested that monotherapy of nivolumab has achieved an ORR of 25% in BRAF mutant tumors and 41% in KRAS/BRAF wild-type tumors, the most recent result has proven that nivolumab plus low-dose ipilimumab has achieved satisfying outcome for MSI-H/dMMR metastatic colorectal cancer (Overman et al., 2017; Lenz et al., 2020). The gene discussed is KRAS; the disease is metastatic colorectal cancer.