PBX1 and acute lymphoblastic leukemia: In the present study, we report a case of hyperdiploid B-ALL with a balanced t(1;19) bearing the TCF3-PBX1 fusion gene confirmed by metaphase FISH, which has only been previously reported in a small number of cases and represents a distinct subtype of B-ALL based on the presence of the confirmed fusion gene in conjunction with hyperdiploidy and t(1;19)/der(19)t(1;19).