CD274 and cancer: In primary cancer, CD4/CD3 was positively correlated with Ki-67 (the intratumoral: r=0.410, P=0.042; the peritumoral: r=0.414, P=0.029) and negatively correlated with PD-L1, but the number of positive cases of PD-L1 was small (only one sample expressed PD-L1 in the primary sites and two expressed PD-L1 in the metastatic lesions).