ERG and acute lymphoblastic leukemia: To better understand the potential biological role of intragenic ERG deletions (which associate with specific clinical features and characterize a biologically unique ERG-related ALL subgroup) we aimed to study two possible primary consequences of this aberrations: 1) the expression of aberrant dominant-negative (or gain-of-function) gene products and/or 2) gene dosage dependent reduction of physiological gene products.