The most common co-occurring mutations in AML with biallelic CEBPA mutations are variants in GATA2, WT1 (WT1 transcription factor), TET2 (Tet Methylcytosine Dioxygenase 2), and CSF3R (Colony Stimulating Factor 3 Receptor). The gene discussed is TET2; the disease is acute myeloid leukemia.