Each sample was tested in vivo in cohorts of vehicle (n=5) and alisertib (30mg/kg/day; n=5). All five ALL samples showed significant response (p<0.01 for all five samples compared to their respective vehicle controls by Chi Square analysis)....Our results suggest that TCF3-HLF ALL is a heterogeneous subset of ALL with both different gene expression patterns from TCF3-HLF to other fusions as well as functional drug response.