In the absence of class-defining genetic abnormalities, a separate category of AML with myelodysplasia-related cytogenetic abnormalities incorporates cases with a complex karyotype (defined as ≥3 unrelated clonal chromosomal abnormalities) and/or other unbalanced chromosomal changes that previously fell into the prior AML-MRC category but lack a TP53 mutation or myelodysplasia-related gene mutations, i.e., del(5q)/t(5q)/add(5q), –7/del(7q), +8, del(12p)/t(12p)/add(12p), i(17q), –17/add(17p)/del(17p), del(20q), or idic(X)(q13) [106]. Here, TP53 is linked to acute myeloid leukemia.