HDAC9 and obesity due to melanocortin 4 receptor deficiency: In enteroids from patients with obesity, treatment with the HDAC inhibitor SAHA induced an increase (p < 0.05) in ALPI (3.9-fold) mRNA expression and a decrease (p < 0.01) in MUC2 (0.2-fold) and CHGA (0.2-fold) mRNA expression (Figure 6A).