Background: Forkhead box protein K1 (FOXK1) is a member of the human Forkhead-box (FOX) family of proteins. The Forkhead-box domain is a highly conserved DNA binding domain of about 100 amino acids found in proteins that function as transcriptional regulators. FOXK1 also bears an FHA (forkhead-associated) domain, a putative nuclear signaling domain that binds phospho-peptides. FOXK1 has been shown to play a role in the regulation of myogeneic progenitor cells and skeletal muscle regeneration.