1 Antimicrobial peptides in echinoderm host defense Chun Li 1 *, Hans-Matti Blencke 1,2 , Tor Haug 1,2 , and Klara Stensvåg 1,2* 1 Norwegian College of Fishery Science, Faculty of Biosciences, Fisheries and Economics, UiT The Arctic University of Norway, Breivika, N-9037 Tromsø, Norway 2 Centre for Research-based Innovation on Marine Bioactives and Drug Discovery (MabCent-SFI), UiT The Arctic University of Norway, N-9037 Tromsø, Norway *Corresponding authors. E-mail address: Chun.Li@uit.no (C. Li) Tel.: +47 77 64 63 28; Fax: +47 77 64 51 10. E-mail address: Klara.Stensvag@uit.no (K. Stensvåg) Tel.: +47 77 64 45 12; Fax: +47 77 64 51 10.