In the previous study by Le et al., patients with MMR-deficient colorectal cancers had higher rates of immune-related objective responses and longer immune-related progression-free survival following pembrolizumab treatment than those with MMR-proficient colorectal cancers, and similar responses were observed in patients with MMR-deficient non-colorectal cancers [29]. The gene discussed is MRC1; the disease is colorectal cancer.