Functional genetic analysis using RNA interference (RNAI) revealed that CLIPA28 is essential for the melanization of Plasmodium berghei parasites in refractory mosquitoes, and for mosquito resistance to fungal infections We further show, using combined biochemical and genetic approaches, that CLIPA28 is member of a network of at least four CSPHS, whereby members are activated in a hierarchical manner following septic infections.