In mouse models of obesity-associated and aging-associated BAT dysfunction and inactivation, induction of Adcy3-at expression persisted in BAT of HFD-fed C57BL/6N male mice (Extended Data Fig. 4h), while cold-evoked Adcy3-at induction was blunted in iWAT of obese mice, a finding also observed for BAT markers like Ucp1, iodothyronine deiodinase 2 (Dio2) and ELOVL fatty acid elongase 3 (Elovl3; Extended Data Fig. 4i). Here, DIO2 is linked to obesity due to melanocortin 4 receptor deficiency.