CD4 and colorectal cancer: The results illustrated that the patients treated with combined therapy had a higher MD than those treated with chemotherapy alone (MD 0.32; CI: 0.25–0.40, p<0.01; I2 = 46%) (Fig 3C), which explains that SFI combined with chemotherapy in the treatment of colorectal cancer can significantly increase extent of the CD4+/CD8+ expression.