Because LM cell recruitment did not seem to be affected by obesity, to further investigate the mechanism underlying the decrease in LM2 cell number during obesity, we assessed apoptosis (terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay) and proliferation (Ki67 staining) in both recently recruited and resident myeloid cells. The gene discussed is MKI67; the disease is obesity due to melanocortin 4 receptor deficiency.