In vitro atorvastatin reduces interferon-beta effects. Mononuclear cells from 21 therapy-naive patients with relapsing-remitting multiple sclerosis were pretreated at 24 hours with 10-μM atorvastatin, then induced with 160 U/mL of interferon-beta-1b for 45 minutes (phosphorylated/activated STAT transcription factors) and 24 hours (downstream proteins, STAT1, STAT2, interferon regulatory factor 1 [IRF-1], and myxovirus resistance 1 [MxA]). Proteins were quantified with Western blots and normalized with actin. *P<.001 vs no-statin control, †P<.05. MEV indicates 100-μM mevalonate. Error bars indicate SEM.