This gene is a member of the host cell factor family and encodes a protein with five Kelch repeats, a fibronectin-like motif, and six HCF repeats, each of which contains a highly specific cleavage signal. This nuclear coactivator is proteolytically cleaved at one of the six possible sites, resulting in the creation of an N-terminal chain and the corresponding C-terminal chain. The final form of this protein consists of noncovalently bound N- and C-terminal chains. The protein is involved in control of the cell cycle and transcriptional regulation during herpes simplex virus infection. Alternatively spliced variants which encode different protein isoforms have been described; however, not all variants have been fully characterized.