Reason for name "Motile sperm domain-containing protein 2" if it has nothing to do with sperm
As you can tell from the gene name, it contains a domain (a "major sperm protein domain)") that happens to have "sperm" in its name. That doesn't mean that the protein itself have anything to do with sperm. There are a lot of examples of gene names like this, where they're named after some random domain they contain until later their names are changed. MSOPD2 has only had a known function for a few months.

As an aside, if you actually work on this gene then one would hope that you would have taken the whopping 5 minutes required to figure this out in pubmed.