C5AR1 and hepatocellular carcinoma: To investigate whether LukS-PV inhibits the proliferation of HCC cells by targeting C5aR1, we knocked down C5aR1 expression in HepG2 cells, which are relatively high C5aR1 expression; induced the ectopic expression of C5aR1 in Hep3B cells, which are relatively low C5aR1 expression.