CD4 and neoplasm: In this study, we enrolled 330 CRC patients by the match of pMMR (167) and dMMR (163) and explored the relationship between MMR status and other clinicopathologic characteristics, especially some important anti-tumor immune molecules such as MHC class I, CD3, CD4, CD8, CD56, PD-1 and PD-L1 to explain the better effect of anti-PD-1 therapy in dMMR group and explore some other possible efficacy predictors besides MMR status.