In mammals, MEKK3s have been shown to act as crucial regulators of innate immunity against pathogen infections via the involvement of interleukin-1 receptor (IL-1R) and toll-like receptor (TLR) -mediated NF-κB, JNK and p38 cascades, which are essential for inducing the expression of proinflammatory cytokines (12, 23–25). The gene discussed is NFKB1; the disease is infection.