UCP1 and obesity due to melanocortin 4 receptor deficiency: To test a role for IL18 and NCC in BAT in controlling obesity and glucose intolerance in response to HFD and thermogenic stimulation, we selectively depleted IL18 or NCC in UCP1-expressing brown and beige adipocytes by crossbreeding the Ucp1Cre mice with the Il18fl/fl or Nccfl/fl mice to generate Il18fl/flUcp1Cre and Nccfl/flUcp1Cre mice.