May be involved in regulating functions and processes within the digestive system (Probable). Shows serine protease inhibitory activities (PubMed:31842369). Strongly inhibits trypsin (Ki=0.05 nM), chymotrypsin (Ki=7.4 nM), and kallikreins (KLK5, KLK7 and KLK14) (PubMed:31842369). May be involved in regulating functions and processes within the digestive system (Probable). Shows serine protease inhibitory activities (PubMed:31842369). Strongly inhibits trypsin (Ki=0.08 nM), chymotrypsin (Ki=2.9 nM), and kallikreins (KLK5, KLK7 and KLK14) (PubMed:31842369). Is resistant to heat-induced denaturation (95 degrees Celsius). Mostly expressed in the mesenterial filaments, with relatively low levels (3-4 fold) of expression in the acrorhagi. Expression levels in tentacles are detectable, but very low. Average mass. Average mass. Belongs to the venom Kunitz-type family. Sea anemone type 2 potassium channel toxin subfamily.