GDNF and trisomy 21: Another study found that administration of glial cell derived neurotrophic factor (GDNF) rescued megacolon, prevented death and stimulated ENS regeneration in the Holstein (a model for trisomy 21-associated HSCR), TashT (a model for male-biased HSCR) and Piebald-lethal (a model for EDNRB mutation- associated HSCR) mice models (Soret et al., 2020).