Finally, we classified 1,013 CRC patients into four subgroups: non-MSI CRC patients with POLE mutations (POLE group, 0.4%, n = 4), MSI CRC patients with extensive MLH1 methylation (MSI-M group, 2.9%, n = 29), MSI CRC patients with unmethylated MLH1 (MSI-U group, 3.6%, N = 36), and non-MSI CRC patients (non-MSI group, 93.2%, n = 944, Fig. 3d). Here, MLH1 is linked to colorectal carcinoma.