GPR55 and hepatocellular carcinoma: Findings of clinical studies in HCC and colon cancer patients lend support to this hypothesis and basic studies, including in vitro experiments with Colon 26 cells stably expressing SPL and GPR55, and in vivo experiments using xenograft models have revealed that SPL plays important roles in facilitating cell proliferation via both GPR55‐dependent and GPR55‐independent pathways (Figure 7).