Using this method, the B-ALL cell lineage is currently defined as: (i) ‘pro–B-ALL’, when the cells originate from early pro–B lymphoblasts that express CD19 and CD38 at the plasma membrane; (ii) ‘common B-ALL’, when the cells originate from late pro–B lymphoblasts or intermediate B-cell precursors, as identified by the expression of CD19, CD38, CD10, and CD79a at the plasma membrane; and (iii) ‘pre–B-ALL’, when the cells originate from more committed progenitors defined as pre–B lymphoblasts that express CD19, CD38, CD10, CD79a, CD20, CD22, and immunoglobulins at the plasma membrane7. Here, MME is linked to acute lymphoblastic leukemia.