Combination of HNHA and sorafenib produced antitumor effects in ATC cell xenografts in vivo. Athymic nude mice with established tumors were treated with the indicated inhibitors. Data represent the mean tumor volumes. HNHA and sorafenib combination therapy induced more potent inhibition of tumor progression than did HNHA or sorafenib alone, resulting in the maximum prolongation of survival in mice with ATC (8505C, A–D; SNU-80, E–H; and GSA1, I–L) xenografts (n = 10 mice/group) (A, E, and I). “No tumor + HNHA + sorafenib” indicates HNHA and sorafenib combination-treated mice with no xenograft; no evidence of systemic toxicity or treatment-related death was found in HNHA and sorafenib combination-treated groups (B, F, and J). The compounds had no significant effect on mouse body weight (C, G, and K). Weights of the dissected tumors (D, H, and L). Immunoblot analysis of total proteins isolated from the tumors (M). * P < .05 vs. control, ** P < .01 vs. control, *** P < .005 vs. control.