In accordance with relevant research, adipocyte expansion of Mus musculus with obesity was mitigated by increasing bilirubin levels; at the same time, the expression of mRNA coding for NAD(P)H oxidase components and inflammatory markers in adipose tissue, such as TNF-α and HMGB1, was restricted; this suggested that bilirubin could improve insulin resistance by modifying inflammation and mitigating oxidative stress [30]. Here, FMO5 is linked to obesity due to melanocortin 4 receptor deficiency.