For the very high immunogenicity (abundance of pre-existing tumor-antigen-restricted CD8+T-cells), with upregulation of immune checkpoint and other immunosuppressive genes, the POLEmut ECs together with MSI ECs, as “hot tumors”, are promising candidates for checkpoint blockade immunotherapy, being considered the best molecular types that can respond to anti-PD-1/PDL1 treatment (16). The gene discussed is PDCD1; the disease is neoplasm.