GHRL and ischemia: Another possibility is that ghrelin activates Clu+ revival stem cells indirectly via the vagus nerve connecting the central nervous system to each intestinal crypt (Ten Hove et al. 2021), as suggested by our studies showing that vagotomy abolished ghrelin’s enteroprotection in sepsis enteropathy intestinal ischemia/reperfusion, and RCI models (Shah et al. 2009; Wu et al. 2008; 2009).