PECAM1 and neoplasm: In congruence with in vitro results, the IHC staining analysis showed that protein expressions of VEGFA and CD31 in the tumor tissues of xenografted mice from the LRRC1-OV group were remarkably increased compared with those from the EV group, indicating that LRRC1 plays a critical role in the promotion of tumor growth and tumor angiogenesis of HCC in vivo (p < 0.05, Figure 4C,D).