FOX proteins are transcription factors that play important roles in regulating the expression of genes involved in cell growth, proliferation, differentiation, and life expectancy. Defining for FOX proteins is the forkhead box motif, a sequence of 80 to 100 amino acids, that binds to DNA. FOXA1 is a hepatocyte nuclear factor activating liver-specific transcripts such as albumin and transthyretin, and interacting with chromatin. It is highly expressed in prostate and ESR1-positive breast tumors. Overexpression is found in esophageal and lung adenocarcinomas.