LEP and obesity due to melanocortin 4 receptor deficiency: ACBP/DBI mRNA and protein levels in the liver increase with aging, high‐fat diet‐induced obesity of normal mice or obesity of leptin‐deficient Ob/Ob mice (Anagnostopoulos et al., 2022; Bravo‐San Pedro, Sica, Martins, Pol, et al., 2019; Wang et al., 2021).