FANCD2 (Fanconi anemia, complementation group D) is a protein involved in DNA repair. Defects in FANCD2 are the cause of Fanconi anemia, a heterogenous autosomal recessive disorder characterized by congenital malformations and a predisposition to cancer. The FANCD2 gene is one of 13 complementation groups that include FANCA, FANCB, FANCC, FANCD1/BRCA2, FANCD2, FANCE, FANCF, FANCG, FANCI, FANCJ/BRIP1, FANCL, FANCM, and FANCN/PALB2. The FANC members are not homologous proteins but are related by their assembly into a common nuclear complex.