AKT1 and leukemia: In the pediatric setting, the PI3K/AKT/mTOR signaling axis has been described as abnormally activated in both hematologic and solid tumors, mainly as a consequence of chromosomal gains amplifying the AKT1 gene (described in rare cases of leukemia) [190,191,192] or the aberrant expression of PI3K isoforms [193].