The inhibitory effects of troglitazone are mediated by MAP kinase. Peripheral blood adhering monocytes were cultured with GM-CSF and IL-4 in the presence or absence of troglitazone (A,B) and 15d-PGJ₂ (C,D), respectively. Fifteen minutes, 1 hour, and 24 hours before analysis, cells were incubated with TLR2L Pam₃Cys, TLR3L Poly(I:C), TLR4L LPS, and TLR7L R848, respectively. Phosphorylation state of MAP kinase ERK1 (A,C) and p38 (B,D) was analyzed using phosphospecific antibodies.