Chromatin immunoprecipitations were performed with cross-linked chromatin from 4 x 10 6 NK-92 cells starved of IL-2 overnight then treated with IL-12 (10 ng/ml) for 4 hr and either 10 μl of Stat4 (C46B10) Rabbit mAb #2653 or 2 μl of Normal Rabbit IgG #2729 using SimpleChIP ® Enzymatic Chromatin IP Kit (Magnetic Beads) #9003. The enriched DNA was quantified by real-time PCR using human IRF-1 promoter primers, human PRF1 promoter primers, and SimpleChIP ® Human α Satellite Repeat Primers #4486. The amount of immunoprecipitated DNA in each sample is represented as signal relative to the total amount of input chromatin, which is equivalent to one.