Since many of the Wnt/β-catenin target genes that were affected by MRP4-kockdown in the mouse uterus (Figure 4A) are associated with tumorigenesis (e.g. Ccnd2, Twist1, Id2, Sox9, Wisp1, Met, Fzd7, Axin2, Jag1, CD44, Fgf9, and Fn1) 36-47, we next examined possible correlation of MRP4 with Wnt/β-catenin signaling during detrimental transformation of the endometrium (e.g. endometriosis and endometrium cancer) in humans. The gene discussed is ID2; the disease is endometriosis.