Dickkopf‐1 (DKK1) and cytoskeleton‐associated protein 4 (CKAP4) are necessary for hepatocellular carcinoma tumor formation in vivo. (A, B) Lysates from Hep3B cells stably expressing control or two independent DKK1 shRNAs were probed with the indicated Abs (A). Hep3B cells stably expressing control (n = 8) or two independent DKK1 shRNAs (#1, n = 8; #2, n = 7) were subcutaneously inoculated into immunodeficient mice (B). Tumor volumes are presented as the mean ± SE, and tumor weights are plotted as violin plots with median values indicated by the red lines and the interquartile ranges by the dotted lines. **p < 0.01 (ANOVA post hoc test). (C, D) Lysates from Hep3B cells stably expressing control shRNA, CKAP4 shRNA, or CKAP4 shRNA and CKAP4‐HA were probed with the indicated Abs (C). Hep3B cells stably expressing control shRNA (n = 9), CKAP4 shRNA (n = 7), or CKAP4 shRNA and CKAP4‐HA (n = 6) were subcutaneously inoculated into immunocompromised mice (D). Scale bars, 10 mm. *p < 0.05 (ANOVA post hoc test). n.s., not significant