TFAP4 and adenoma: These signatures also showed preferential enrichment among the mRNAs downregulated after deletion of Ap4. Moreover, mRNAs encoding for proteins involved in Wnt/β-catenin and Notch signaling, which control the homeostasis of ISCs16,17, were also preferentially downregulated in Ap4-deficient adenomas (Fig. 4a, b, Supplementary Fig. 3c, Supplementary Data 2).