HSFY1 is a member of the heat shock factor (HSF) family of transcriptional activators for heat shock proteins. This gene is a candidate gene for azoospermia, since it localizes to a region of chromosome Y that is sometimes deleted in infertile males. The genome has two identical copies of this gene within a palindromic region; this record represents the more centromeric copy. Alternative splicing results in multiple transcript variants encoding distinct isoforms. Recombinant human HSFY1 protein, fused to His-tag at N-terminus, was expressed in E.coli .