CD274 and neoplasm: C5a expression was significantly correlated with the MMP9 (p = 0.000), vimentin (p = 0.000), tumor PD-L1 (p = 0.001), stromal PD-L1 (p = 0.002), PD-1 (p = 0.003), and Ki67 (p = 0.000) expression levels.