Whereas HSCs are Lin− Sca1+cKit+CD48−CD150+ and MPP linage is Lin− Sca1+cKit+CD48+CD150−, the ML23 leukemia cell linage is cKit−/+Sca1+CD150+CD48−/+, which suggests heterogeneous subpopulations with respect to the cKit and CD48 markers. The gene discussed is CD48; the disease is leukemia.