C9 and infection: Seven genes of innate immunity (mst1ra, il-1β, tnfr1, p22phox, nkef-b, sla1, cd97), seven genes of adaptive immunity (stat4, igm, cd83, foxp3, tgf- β, il16, mhcII) and complement c9 were significantly higher expressed in NO sticklebacks infected with Pacific S. solidus in comparison to infection with Atlantic S. solidus (Additional file 1: Table S16).