Human IPE and RPE exhibit different sensitivities in response to PAMPs. IPE (A, B and C) and RPE (D, E and F) from the same donor were stimulated with PAMPs such as Pam3CSK4.3HCl, Poly(I:C), LPS (serotype O111:B4), Flagellin, MALP-2 (macrophage activating lipopeptide-2), Poly(U) and CpGODN2395 at a lower (A and D) and higher dose (B, C, E and F), under serum free condition for 24 hours (control = basal media). Conditioned media were collected and assayed for IL-8 or MCP-1 by ELISA. Data represents mean ± SD (N = 3). One-way ANOVA and Dunnett’s posttest was used to compare ligand-treated samples to controls, *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001. Results are representative of three experiments (the results are consistent from three donors).