First evidence about p53’s involvement in obesity came from a study done in genetically obese (ob/ob) mice and showed p53 mRNA and protein induction in epididymal WAT of these animals, which correlated inversely with sterol regulatory element-binding transcription factor 1 (Srebf1) mRNA expression. Here, SREBF1 is linked to obesity due to melanocortin 4 receptor deficiency.