FAAP24 (FA core complex associated protein 24) functions as a critical DNA repair protein that works in partnership with FANCM to maintain genome stability. Primary Function: FAAP24 serves as a DNA-binding partner of FANCM that recruits the FA core complex to sites of DNA damage, particularly at branched DNA structures and single-stranded DNA 1. The protein plays a central role in the Fanconi anemia (FA) pathway, where it facilitates monoubiquitination of FANCD2-FANCI upon DNA damage 2. Mechanism: FAAP24 operates through two distinct mechanisms: it cooperatively activates FA pathway signaling with FANCM and independently promotes ATR-mediated checkpoint activation in response to DNA crosslinking agents 3. The FANCM-FAAP24 complex remodels stalled replication forks through ATP-dependent branch migration, which is essential for activating ATR signaling 4. Disease Relevance: FAAP24 loss induces chr19 instability and hypersensitivity to DNA crosslinking agents 1. Mutations in FAAP24 have been identified in castration-resistant prostate cancer patients and colorectal cancer families with multiple primary tumors, where the protein's disruption sensitizes cells to PARP inhibitors 56. Clinical Significance: FAAP24 alterations are part of broader DDR/FA signaling network mutations affecting cancer susceptibility and therapy response across multiple tumor types 7.