The main cytogenetic–molecular entities in AML are translocations 15;17 (t(15;17)(q22,q21)), 8;21 (t(8;21)(q22;q22.1)), and 9;22 (t(9;22)(q34.1;q11.2)); inversions 16 (inv(16)(p13q22) or t(16;16)(p13;q22)) and 3 (inv(3)(q21.3q26.2) or t(3;3)(q21.3;q26.2)); mutations in TP53, NPM1, FLT3, and IDH; complex karyotypes; and others. The gene discussed is IDH2; the disease is acute myeloid leukemia.