ChIPs in pre-B-ALL cells (697) that carry the E2A-PBX1 fusion and express only BAFFR, mimicking patients' phenotype, evaluated whether E2A-PBX1 binds in vivo to sequences of the BAFFR gene that include PBX consensus motifs (promoter, intronic and 3′UTR). The gene discussed is PBX1; the disease is acute lymphoblastic leukemia.