CREBBP and obesity due to melanocortin 4 receptor deficiency: Obesity is typically defined as a multifactorial chronic disease with several causes resulting in excessive body fat accumulation, which sometimes is associated with poor health conditions.339 Zhou et al.340 found that selective inhibition of the HAT domain of CBP/p300 histone acetyltransferases, by A-485, markedly decreased the fat mass in obese mice.