The expression of tight junction proteins like (mRNA and protein) occludin, zonulin-1 (Zo1), and junctional adhesion molecule (Jam), as well as mucin synthesis gene mRNAs (Muc2 and Muc6), was significantly decreased in Lepob/ob mice (Figures 1(b)–1(d)), suggesting that obesity resulting from leptin deficiency decreased expression of tight junction and mucin synthesis genes, which might result to leaky gut with increased permeability. The gene discussed is MUC5AC; the disease is obesity due to melanocortin 4 receptor deficiency.