Ticks feed on their vertebrate hosts for number of days, providing enough time for development of an effective immune response. To overcome this, tick saliva contains a complex mixture of active substances which mediate host defense mechanisms. Extremely important role at the tick-host interface is played by the protease inhibitors. In this work, we have focused on the protein named Ixocludin 2, a member of the Kunitz type/Bovine trypsin inhibitors of serine proteases, related also to the potassium channel blockers toxins. Three different expression systems (Escherichia coli, Chinese hamster ovary and Pichia pastoris) were tested to prepare an active recombinant Ixocludin 2, out of which, only bacterial system was in part successful.