Considering that MIH4 efficacy mainly correlates with intratumoral PD-L1 expression, these findings indicate that Capecitabine in combination therapy promoted microbial S1P production and synergistically enhanced the efficacy of MIH4 by up-regulating PD-L1 synthesis of CRC tissues (Figures 3H and 3I). The gene discussed is CD274; the disease is colorectal carcinoma.