Wang et al. (2018b) further validated the in vivo antitumor effects of combining bufalin with sorafenib (Wang et al., 2018b). In the SMMC-7721 cells xenograft model, bufalin (1 mg/kg, 5/week, IP), when combined with sorafenib (30 mg/kg/day, 5/week, oral) showed better tumor-reducing effects as compared to mono-therapy. p-AKT, VEGF, and mTOR but not p-ERK in tumor tissues were found to be downregulated (Wang et al., 2018b), suggesting that this combination might work differently in vivo as compared to in vitro (in which p-ERK was also downregulated by bufalin and sorafenib). Here, MTOR is linked to neoplasm.