HMOX-1–/– HIS mice have reduced murine macrophages but no decrease in monocytes. HMOX-1–/– and HMOX-1+/+ MSRG47 mice were hHSC engrafted. At 12 weeks after engraftment, spleen and liver tissues were harvested for single-cell preparation. Mouse monocytes and macrophages were analyzed in spleen by examining mouse CD45+ leukocytes for CD11b+/CD14+ (monocytes), with macrophages denoted as mouse VCAM+/mouse F4/80+ cells (A). (B) For liver analysis, mouse CD45+ leukocytes were analyzed for CD11b+ cells (monocytes) and macrophages denoted as a subset of CD11b+ cells that are mouse VCAM+/mouse F4/80+. (C) Human monocytes and macrophages were analyzed in spleen and liver by examining human CD45+ leukocytes for CD14+ (monocytes) with CD36+/CD206+ macrophages examined as a subpopulation of human CD14+ cells in spleen and liver. At least 3 independent experiments were performed. Data represent the mean ± standard error of the mean, with individual mice shown. Statistical analysis was evaluated by unpaired Student t test. VCAM, vascular cell adhesion molecule.