MUC2 and obesity due to melanocortin 4 receptor deficiency: This is particularly interesting since depletion [58] or reduced production of mucosal-barrier-related molecules, such as Muc2 and goblet cells, has been associated with systemic inflammatory responses and the appearance of several diseases like colorectal cancer, Crohn’s disease, ulcerative colitis, obesity, and T2D [42,59].