Chromatin immunoprecipitations were performed with cross-linked chromatin from 4 x 10 6 BaF3 cells starved of IL-3 for 6 hours followed by induction with IL-3 for 45 minutes, and either 10 μl of Stat5 Antibody 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 SimpleChIP® Mouse CIS Intron 1 Primers #5131, mouse SOCS3 promoter primers, and SimpleChIP® Mouse RPL30 Intron 2 Primers #7015. 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.