Anticoagulant protein that inhibits the serine proteases trypsin and elastase, but not thrombin (PubMed:25708749). The anticoagulant effect of this recombinant protein on blood clotting is found only in the activated partial thromboplastin time (APTT) assays, but not in the prothrombin time (PT) assays (PubMed:25708749). Primarily expressed in salivary glands and weakly expressed in the midgut of fed ticks. By blood feeding. Expression is most important during the early stage of feeding.