TMBIM4 and hepatocellular carcinoma: Western blot analysis revealed that S1R protein levels were significantly increased in SMMC‐7721 and PLC/PRF/5 cells following treatment with sorafenib (Figure 1C,D), as they were in Hep G2 and Huh‐7 cells (Figure 1A,B).21 Furthermore, sorafenib up‐regulated S1R protein levels in these HCC cells in a time‐dependent manner (Figure 1A‐D).