Sequencing of the human BOLL gene in 200 fertile and infertile men revealed few sequence variants (Xu et al., 2003, Westerveld et al., 2005), in comparison to human DAZL, which has common variants at approximately 1 in every 100 basepairs (Teng et al., 2002, Tung et al., 2006). This evidence concerns the gene DAZL and Infertility.