NR1D1 and obesity due to melanocortin 4 receptor deficiency: It is noteworthy that the protective effects of SR9009 against HFD-induced obesity may depend not only on REV-ERBα/BMAL1 but also on REV-ERBβ/BMAL1 because SR9009 is a dual agonist of REV-ERBα and REV-ERBβ, both of which repress Bmal1 transcription and expression26,39, and REV-ERBβ is also expressed in the intestine40.