Based on limited published evidence, PRSS51 is a serine-type peptidase localized to the plasma membrane involved in protein processing. GO annotations indicate serine protease activity at the plasma membrane. However, functional studies demonstrate that PRSS51 is not required for male fertility in mice, as PRSS51 single knockout mice are fertile 1. PRSS51's specific cellular substrates and physiological roles remain unclear, with no independent functional characterization currently available in the literature.