Human total monocyte populations,59 as well as mouse inflammatory (CD115+Ly6Chigh)60 and noninflammatory monocytes (CD115+Ly6Clow),49 exhibit circadian oscillations in their numbers in blood, peaking during the behavioral rest phase of humans and mice and exhibiting a trough during the active phase.49 This rhythm of Ly6Chigh monocytes is disrupted on myeloid-cell–specific deletion of Bmal1 (Lyz2cre:Bmal1flox).60 This deletion has been shown to affect the overall metabolism of the affected organism, leading to obesity.60 This evidence concerns the gene CSF1R and obesity due to melanocortin 4 receptor deficiency.