Interestingly, genes involved in epigenetic functions such as TET2 (5%), SUZ12 (5%), EP300 (5%) as well as genes that possess transcriptional activity like RUNX1 (9%), PTEN (8%), CBL (5%), or BCOR (4%) were mutated in the range of 5-10% of our T-ALL patients. The gene discussed is PTEN; the disease is acute lymphoblastic leukemia.