A tick saliva serpin, IxsS17 inhibits host innate immune system proteases and enhances host colonization by Lyme disease agent. oleh Thu-Thuy Nguyen, Tae Heung Kim, Emily Bencosme-Cuevas, Jacquie Berry, Alex Samuel Kiarie Gaithuma, Moiz Ashraf Ansari, Tae Kwon Kim, Lucas Tirloni, Zeljko Radulovic, James J Moresco, John R Yates, Albert Mulenga