Has antimicrobial activity against E.coli (By similarity). Plays a role in the defense response in the male reproductive tract, contributing to sperm maturation, storage and protection (By similarity). Exon 6 is read in two different reading frames, one resulting in the N-terminal amino acid sequences of EP2A, EP2B and EP2F and the other in the N-terminal sequences of EP2D, EP2E and EP2G. Specifically expressed in caput and proximal corpus of epididymis (at protein level) (PubMed:8167223). Present in the epididymal epithelium and on the sperm surface, with a subacrosomal equatorial distribution on the sperm head (at protein level) (PubMed:8167223). Belongs to the SPAG11 family.