Taken together, our findings collectively indicate that RCE plus Oxa not only increases the abundance of CD8+ T cell infiltration in CRC tumors but also possesses a noteworthy CRC antitumor effect by immune killing through improving CD8+ T cell infiltration into the humanized PD-1/PD-L1 MC38 tumor mouse models. The gene discussed is PDCD1; the disease is neoplasm.