TCF4 and neoplasm: Importantly, the expression of Wnt/β-catenin target genes, including Tcf4, Ccnd1, Axin2, and Lgr5, was observed in later luminal cell branches of hARtg+ cells through cell trajectory plots in comparison to those of hARtg- cells (Fig. 7c vs d), implicating the activation of Wnt/β-catenin signaling during the course of tumor development.