IFNG and colorectal carcinoma: To observe the modulatory role of butyrate in PD-L1 expression of IFN-γ-treated CRC cells, HCT116 and LoVo cells were exposed to butyrate (0, 2, 5, or 10 mM for 24h or 5 mM for 0, 8, 16 or 24h) under the interference of 24h treatment with IFN-γ (20 ng/mL).