Fas-induced pro-inflammatory cytokine production by mϕ is TLR4-dependent. Primary murine peritoneal mϕ from wild-type, Tlr2-/-, and Tlr4-/-mice were treated with mFasL (0.25 μg/ml) for the times indicated (0 - 18 hr). Pro-inflammatory cytokine production was determined by measurement of (A) TNF-α and (B) MIP-2 in culture supernatants by cytokine-specific ELISAs as described in Materials and Methods. Data are presented as mean ± SD of 3 independent experiments, n = 3/group. * P ≤ 0.05; **P ≤ 0.01.