MUC2 and Rectal prolapse: Mice lacking Muc2 (Van der Sluis et al, 2006), Agr2 (Park et al, 2009; Zhao et al, 2010) or having mutations in Muc2 that interfere with initial mucin folding and assembly (Heazlewood et al, 2008) develop spontaneous colitis or display rectal prolapse.