FBL and neoplasm: Importantly, p53 protein levels are largely comparable in epithelial compartment of PyMT-Fib-ZEB1/p53-dcKO versus PyMT-Fib-WT tumours, or in PyMT-cancer cells in the presence of the conditioned medium from ZEB1/p53-deleted CAFs versus control CAFs (Supplementary Fig. 7e, f).