SIVsmm nef alleles inhibit NFAT induction. Analysis of Jurkat cells stably transfected with an NFAT-dependent reporter gene following transduction with the indicated HIV-1 Nef/eGFP constructs and subsequent stimulation with PHA. Levels of NFAT-dependent luciferase reporter activity are the average (± SD) of triple infections. The asterisks denote a statistical significance (P < 0.01) between HIV-1 and SIV Nef activity. Similar results were obtained in two independent experiments.