Mutation of TGF-β receptor type 2 (TGFBR2) leads to the microsatellite instability causing colorectal cancer, and also the loss of function of SMAD4 in the TGF-β signaling pathway promotes the tumor progression and poor survival in colorectal cancer (Itatani et al., 2019). The gene discussed is TGFBR2; the disease is neoplasm.