TSPAN5 and hepatocellular carcinoma: The analysis of the phosphorylation status of ERK1/2 and retinoblastoma protein (Rb) revealed enhanced ERK1/2 phosphorylation and hypophosphorylation of Rb in the HCC xenografts, thereby confirming the role of OIS in TSPAN5-knockdown-mediated anti-tumor effects (Figure 7F,G).