APC and neoplasm: To test this possibility, we utilized an Apc model of tumourigenesis in which the Apc gene, a tumour suppressor and a negative regulator of the Wnt pathway, can be ablated with tamoxifen administration: Apc was deleted in AL, fasted for 24 h (Fasted), and post-fast refed (Refed) states specifically in Lgr5+ ISCs using the Apcloxp/loxp: Lgr5-EGFP-IRES-CreERT2 mouse model with tamoxifen (Fig. 5a–c).