FZD6 and neoplasm: Considering the role of FZD6 in Wnt/β-catenin activation is elusive, we overexpressed FZD6 in β-catenin inhibited cells, and found impaired influence on tumor invasion and self-renewal (Figs. 1l, m), indicating that FZD6 drives liver tumor invasion and liver TIC self-renewal through Wnt/β-catenin signaling.