TCF7L1 and neoplasm: This rewiring includes a switch in the expression of TCF/LEF effectors, where tumours show upregulation of Lef1 and Tcf7, and downregulation of Tcf7l1. This switch may be triggered by the increased β-catenin levels/activity, as similar observations were made when modulating active levels of β-catenin in mammalian nephron progenitor cells33.