CD10+ ancestor cells with germline antigen receptors, but silent TEL/AML1 expression, may reside in the lymphoid stem cell compartment of treated t(12;21)-positive patients and might act as a potential source of cells for late relapses..     ///    "We monitored the responses of patients with pediatric acute lymphoblastic leukemia (pALL) using DNA markers, TEL/AML1 expression, and scanning fluorescence microscopy (SFM). "