Wang H, et al. - Through integrating published MSI associated gene expression data, immune-profiles of microsatellite instability (MSI) subtype colon cancer were identified by the researchers in order to ascertain the relationship of PD-1 ligand (PD-L1) expression, IFN-γ expression signature, tumor mutational burden, and MSI in determining immune checkpoint therapy. PD-L1, IFN-γ and IFN-γ associated genes were highly expressed in the MSI subtype colon cancer patients with favorable effects in colon cancer progress. Wnt-β-catenin and TGFβ signaling pathways (two important factors inhibiting programmed cell death protein 1(PD-1) checkpoint blockade therapy) were negatively related to the status of MSI. Also, the immune-profiles in MSI subtype colon cancer were provided by M1 macrophage infiltration in the tumor environment. Hence, the study exhibited the detailed underlying mechanisms of MSI subtype cancer patients who were sensitive to the PD-1 checkpoint blockade.