PBX1 and leukemia: Several PI3K/AKT/MTOR pathway genes were identified to affect cell proliferation in the shRNA screen (e.g. PIK3CD, AKT2, AKT1, RPS6) (Supplementary Table S3) confirming our previous data about PI3K/AKT/MTOR activation in mouse E2A-PBX1+ leukemia cells [6].