To determine if Nf1 loss was impacting adipocyte differentiation, we isolated ASCs from the SVF population of rat mammary gland before tumor formation and observed decreased differentiation of Nf1-deficient IF/+ ASCs; however, flow cytometry analysis demonstrated that the abrogated differentiation was not due to a decrease in the Lin- CD34+ CD29+ CD90+ CD54− ASC population. The gene discussed is NF1; the disease is neoplasm.