Based on limited published evidence, BPY2B is a Y chrY-linked gene located in the AZFc region. BPY2B is part of a locus involved in male fertility; partial deletions spanning BPY2 to BPY2B occur at comparable frequencies in both infertile and fertile men, suggesting BPY2B alone may not be a primary determinant of male infertility 1. However, complete AZFc deletions (BPY2 to CDY1B) are significantly associated with low sperm concentration and absent in fertile controls, indicating the broader AZFc region containing BPY2B plays a role in spermatogenesis.