IL17A and ventilator-associated pneumonia: However, the same bacterial challenge in mechanically ventilated rats (i.e., VAP rats) led to a significantly lower response for all three IL-17 family cytokines studied (IL-17A, IL-17F, and IL-22) as well as for IFNγ, compared to the infected/non-ventilated control group, although declining trends for IL-6 and IL-1β were also observed.