However, inflammation can also be damaging in the context of TB, as evidenced by the reduced survival and increased immunopathology observed in M. tuberculosis-infected PD1−/− mice (9), interleukin-27−/− (IL-27−/−) mice (10), and C57BL/6 mice following repeated M. bovis BCG vaccination (Koch’s phenomenon) (11). Here, IL27 is linked to tuberculosis.