In the composite ApcMin/+ mice, most Jag1 WT adenomas showed high levels of nuclear ICN1 (Fig. 1c) and total and nuclear Notch2 (Supplementary Fig. 1F) mainly restricted to the epithelial component, compared to the levels detected in tumors lacking Jag1. Further supporting the notion that Jag1 deletion inhibited Notch activity, we observed decreased expression of the Notch target genes Hes1, c-Myc, and Nrarp in Jag1 knockout (KO) compared to WT tumors (Fig. 1d). Here, JAG1 is linked to adenoma.