Predicted to enable serine-type endopeptidase activity. Acts upstream of or within retinal blood vessel morphogenesis. Predicted to be located in extracellular region and membrane. Predicted to be active in extracellular space. Human ortholog(s) of this gene implicated in Kuhnt-Junius degeneration; age related macular degeneration 13; atypical hemolytic-uremic syndrome; complement factor I deficiency; and macular degeneration. Orthologous to human CFI (complement factor I).