MUC21 and type 1 diabetes mellitus: Conte et al. reported that reduced mRNA expression of several mucins (MUC2, MUC12, MUC13, MUC15, MUC20, MUC21) were found in type 1 diabetes patients which companied with higher percentages of effector T cells such as T helper (Th) 1, Th17 and TNF-α+ T cells 29.