In order to model the continuum of leukaemia based on the age relationship estimated between humans and mice26, we isolated murine lin-sca1+cKit+ (LSK) cells, which include the long- and short-term HSCs, and myeloid progenitor populations (CMPs and GMPs) from different ages of mice (prenatal and postnatal) to represent infant/prenatal origins (foetal liver (FL)), childhood (BM from 3 week(w)), young adult (10 w) and middle/old age (>52w) C57BL/6 mice. The gene discussed is KIT; the disease is leukemia.