This unique repeated stimulation and withdrawal of ovarian hormones in MGs, in a way analogous to ultraviolet light exposure in skin or colitis in small intestine48, 49, may trigger an imbalance of proliferation versus apoptosis between Trp53-null and their neighbouring WT luminal MECs, which canresult in a net accumulation of Trp53-null luminal MECs in nulliparous mice over time. Here, TP53 is linked to colitis.