STAT5 regulates bcl-2 posttranscriptionally through the mIR-15/16 cluster. (A) Level of miR-15a, miR-15b, and miR-16 was quantitated by RT-PCR from wild-type or STAT5ab^null/null mast cell cultures that were transduced with either IR-GFP–, STAT5a-, or STAT5aΔN-expressing vectors (*IR vs STAT5a, P < .05; **STAT5a vs STAT5aΔN, P < .05; Student t test). (B) The level of miR-15a, miR-15b, and miR-16 was assayed in BaF3 cells expressing IR-GFP, STAT5a^S711F, or STAT5aΔN^S711F; *STAT5a^S711F vs STAT5aΔN^S711F, P < .05. Error bars represent SD of the mean. (C) Shown is the conserved STAT5-binding site in the promoter of miR-15b/16-2. The numbers indicate the distance upstream from the start site for miR-15b. (D) ChIP data display STAT5a^S711F and STAT5aΔN^S711F bound to the conserved binding site near the miR15/16 cluster in BaF3 cell extracts. The nonconserved site is approximately 8 kb upstream of the starting site of miR-15b and is included as a control.