In MMRd tumors, resistance following anti-PD-1 treatment is driven by the expression of TIM3, LAG3, CTLA4, and TIGIT by TILs, as well as tumor clonal selection and the expression of TREM2, CSF1R, IFITM, TMEM176B and IL1B by myeloid cells. This evidence concerns the gene CTLA4 and neoplasm.