FLLL32 inhibited IL 6 signaling but did not modulate IFN-γ or IL 2 induced signaling in PBMCs. PBMCs from healthy donors were pre-treated for 16 hours with FLLL32 and subsequently treated with (A) IL 6 (0.1 ng/mL) or (B) IFN-γ (10 ng/mL) for 15 minutes. pSTAT3 and pSTAT1 were evaluated by immunoblot analysis. (C) The expression of the IFN-γ-stimulated gene, IRF1 was evaluated by Real Time PCR following a 1 hour pre-treatment with FLLL32 and subsequently stimulated with IFN-γ (10 ng/mL) or PBS for an additional 4 hours. Real Time PCR data were expressed as fold change versus DMSO-pre-treated cells stimulated with PBS. Data were normalized to 18s rRNA levels. (D) PBMCs were pre-treated for 16 hours and subsequently treated with 8 nM IL 2 for 15 minutes. IL 2-induced pSTAT5 was evaluated by immunoblot analysis. All data are representative of PBMCs from two separate healthy donors.