A male form of "the pill" has stymied researchers for years, but now a new study finds that such male birth control may be possible by blocking a single protein in sperm cells.
In a mouse study, the researchers focused on a protein called calcineurin, which is found in the sperm-producing cells of the testes as well as other cells in the body.
The researchers genetically engineered mice so that they lacked a gene that makes part of the calcineurin protein but is activatedonly in sperm-producing cells. When these mice had sex, they were infertile, the researchers said. (This genetic engineering experiment was done as a proof of concept, to show that this gene affects sperm,).