DEFA5 and obesity due to melanocortin 4 receptor deficiency: Treatment with 1 mM DB for 30 minutes also reduced α-defensin 5 expression by 37% ± 9% (P < 0.05) and lysozyme by 32% ± 9% (P < 0.05) but not α-defensin 6 expression in primary crypts from patients with obesity (Figure 3, A and B).