ACTA1 and obesity due to melanocortin 4 receptor deficiency: In this context, it is noteworthy that, in generically obese (ob/ob) mice, whose abdominal circumference was increased during the course of obesity to the same level as pregnant mice at 16 dpc (Supplementary Fig. 5B), the populations of α-SMA+ dermal fibroblasts and Ki67+ and Tbx3+ IFE basal cells in their abdominal skin were decreased compared with wild-type mice (Supplementary Fig. 5C–E).