AML1 mutations were identified in 6.3% of AML patients with chromosomal translocations involving CBF, PML-RARalpha, HOX, or ETS transcription factor (TF) gene families. Rare chromosomal abnormalities, t(16;21) and t(7;11), were also found. This study represents the first series to demonstrate the coexistence of known and novel AML1 mutations with different TF gene mutations. Although the occurrence of two TF gene mutations may appear unnecessary, the possible synergistic mechanism between different TF gene families cannot be excluded and needs to be further explored.