LGR5 and colitis: Several additional markers label both active cycling ISCs and quiescent ISCs including Bmi1, Lrig1, Hopx, mTert, Krt19, Clu, Mex3a, Atoh1 and when expressed can eventually give rise to Lgr5+ ISCs after injury-induced depletion of the Lgr5+ ISC pool, such as following γ-irradiation, colitis, or during experimental targeted ablation [20,21].