addition of several arginine-specific serine proteases to culture medium conditioned by fibroblasts results in the proteases being taken into sodium dodecyl sulfate-stable complexes with a secreted factor termed protease nexin ( pn ) ( baker , j. b. , low , d. a. , simmer , r. l. , and cunningham , d. d. ( 1980 ) cell 21 , 37-45 ) .
C1327616
secreted
C0007634
cell