Clonal Heterogeneity in TEL/AML1+ Acute Lymphoblastic Leukemia (ALL): A Clinical Appraisal

Introduction:In TEL/AML1+ ALL, the formation of the fusion gene is frequently followed by clonal evolution, with the acquisition of additional aberrations, some involving the TEL and AML1 genes. The resulting variant subclones often coexist at diagnosis, but the clinical significance of this heterogeneity is unclear.