Fox-3, also known as NEUN, HRNBP3, RBFOX3 (RNA binding protein, fox-1) or Fox-1 homolog C, is a 350 amino acid protein that contains one RRM (RNA recognition motif) domain. Localized to both the nucleus and cytoplasm, Fox-3 is suggested to regulate alternative splicing events. Fox-3 is encoded by a gene located on human chromosome 17, which is comprised over 2.5% of the human genome and encodes over 1,200 genes. Two key tumor suppressor genes are associated with chromosome 17, namely, p53 and BRCA1. Tumor suppressor p53 is necessary for maintenance of cellular genetic integrity by moderating cell fate through DNA repair versus cell death. Malfunction or loss of p53 expression is associated with malignant cell growth and LiFraumeni syndrome. Like p53, BRCA1 is directly involved in DNA repair, though specifically it is recognized as a genetic determinant of early onset breast cancer and predisposition to cancers of the ovary, colon, prostate gland and fallopian tubes.