Intriguingly, Sox9 inhibition (whether transient or stable) resulted in significantly reduced expression of AXIN2, a classical Wnt/β-catenin target gene (Fig. 8a and Supplementary Fig. S8a) and of the Wnt receptor and target gene FZD4 (Fig. 8b), in tamoxifen-resistant cells and in triple-negative breast cancer cells. The gene discussed is FZD4; the disease is triple-negative breast carcinoma.