Tick salivary platelet aggregation inhibitor that plays an important part in the anti-hemostatic strategy of ticks. Acts by scavenging thromboxane A2 (TXA2), a potent inducer of platelet aggregation and blood vessel constriction (PubMed:8449906, PubMed:18694828). As a consequence, is a specific inhibitor of collagen-induced platelet aggregation (PubMed:8449907, PubMed:8449906). In addition, it also acts as a potent inhibitor of TXA2-mediated vasoconstriction (PubMed:18694828). Has also been found to bind leukotriene B4 (LTB4) (which also derives from arachidonic acid, as TXA2) with affinities in the nanomolar range (PubMed:18694828). It does not interact with complement protein C5 (PubMed:18694828). Expressed in salivary glands. The N-terminus is blocked. Belongs to the calycin superfamily. Lipocalin family. There are 10 AA differences between the cDNA deduced sequence and the determined protein sequence. These differences are not indicated in the paper.