ALDH1A1 and obesity due to melanocortin 4 receptor deficiency: The RA-related pathways in adipose tissue may influence the whole body metabolism as shown in both Raldh1−/− mice and wild type obese mice with implanted Raldh1-deficient adipocytes that resisted diet-induced obesity (Reichert et al., 2011; Haenisch et al., 2018).