TCF3 and acute lymphoblastic leukemia: However, in B-cell progenitor acute lymphoid leukemia (BCP-ALL) PBX1 is part of the fusion gene TCF3::PBX1, and in Hodgkin lymphoma PBX1 is aberrantly activated, demonstrating that deregulated PBX1 acts as an oncogene in B-cell malignancies [18, 19].