CD274 and neoplasm: Also, while the high degree of intestinal anti-tumor T-cell infiltration in dMMR-MSI-H CRC has been linked to improved activity of PD-1/PD-L1 blockade [96], the greater extent of immuno-inhibitory T-regs and MDSCs infiltration within pMMR-MSI-L tumors may explain their resulting poor immune response [166].