Accumulating reports demonstrated that the phosphorylated-STAT1 (p-STAT1) is a prospective biomarker for investigating anti-PD‐1/PD‐L1 immunotherapy, which could up-regulate PD-L1 expression following IFN-γ stimulation in several types of tumors, highlighting the importance of STAT1 for PD-L1 expression.15, 16, 17 Butyrate, a short-chain fatty acid, is mainly produced by intestinal microbiota, which has been proven to effectively prevent CRC.18 The gene discussed is STAT1; the disease is colorectal carcinoma.