MLLT1 and leukemia: In order to determine the impact of p53 expression in leukemia cells on gene expression in BM-MSC, we compared the ways in which GEP results for BM-MSC exposed to the Trp53 wt and Trp53-/- forms of MLL/ENL+FLT3-ITD, as compared to control BM-MSC, differed from each other.