Consistent with our previous report [20], the present study confirmed the usefulness of CD4+ T-cell density itself as a prognostic factor (Fig. 2A-1, B-1, and C-1), and the combination of low CD4+ cell infiltration and low FOXP3+ cell infiltration was a prognostic factor for low RFS in T3/T4a stage II CRC patients (Fig. 2A-4, B-4 and C-4). Here, FOXP3 is linked to colorectal carcinoma.