Because of our observed luteolin-induced upregulation of FZD6 (Figs 3 and 4), a negative regulator in Wnt signaling pathway28, and the fact that Wnt signaling plays a central role in tumorigenesis and crosstalks with multiple tumorigenic signaling pathways29, we next confirmed the regulatory effect of luteolin on FZD6 as well as Wnt signaling in PCa cells and investigated its role in luteolin-induced suppression of PCa stemness. This evidence concerns the gene FZD6 and posterior cortical atrophy.