TET2 and acute myeloid leukemia: [3] identified an elderly patient with AML who presented with a 1.1 Mb TET2 deletion in one allele, a TET2 nonsense mutation in the other allele, and a NPM1 insertion mutation, who exhibited an astonishing response to a single agent 5′‐Azacitidine (aza) originally given as palliation.