Multifunctionality of the FA pathway. The 15 FA proteins shown here participate in a canonical pathway that repairs DNA cross-links. Eight proteins (FANCA, FANCB, FANCC, FANCE, FANCF, FANCG, FANCL, and FANCM) form a nuclear core complex that facilitates mono-ubiquitination of the ID complex (FANCD2 and FANCI). The ID complex then mediates repair of cross-links in conjunction with FANCD1 (BRCA2), FANCJ (BRIP1), FANCN (PALB2), FANCO (RAD51C), and FANCP (SLX4). FA proteins with non-ICL repair functions that are referenced and discussed in the article are indicated in green.