PBX1 and acute lymphoblastic leukemia: Furthermore, we queried the Mitelman Database of Chromosome Aberrations in Cancer for reported cases of ALL with t(1;19)/der(19)t(1;19), hyperdiploidy, and molecular evidence (FISH and/or PCR) of TCF3-PBX1 fusion, and only identified 5 cases that were positive for the fusion (Table 1).