The cysteine-rich secretory proteins (CRISP) family is a group of four proteins that are strongly expressed in the male reproductive tract and have been implicated in having roles in male fertility. CRISP2, also known as TPX1, has been implicated in the adhesion between spermatids and Sertoli cells, and with CRISP1, is thought to be involved in sperm-egg fusion. CRISP2 has been shown to regulate the Ca2+ influx through ryanodine receptors (RYR) and may influence the acrosome reaction or sperm motility. CRISP2 has also been shown to bind to the mitogen-activated protein kinase kinase kinase 11 (MAP3K11) and localizes to the developing acrosome, suggesting this CRISP2-MAP3K11 complex may have a role in acrosome development.Synonyms: CRISP-2, CT36, Cancer/testis antigen 36, Cysteine-rich secretory protein 2, GAPDL5, TPX1, Testis-specific protein TPX-1