FOXO1A (FKHR or ForkHead in Rhabdomyosarcoma) is a 70 kDa protein which is a member of a subfamily of the forkhead homeotic gene family of transcription factors. Recent studies have shown that this protein can act as either a coactivator or a corepressor of nuclear receptor activity. This action is mediated through the LXXLL motif found in the C terminus of the FOXO1A protein. The specific function of the gene has not yet been determined; however, it may play a role in myogenic growth and differentiation. Chromosomal aberrations involving FOXO1A are a cause of rhabdomyosarcoma 2 (RMS2); also known as alveolar rhabdomyosarcoma.