Effect of MPA on phosphorylation of Stat proteins. 32D cells were treated with 2 μM MPA for the indicated time points. (A) Lysate (30 μg) was used for detection of tyrosine-phosphorylated Stat5. (B) Lysate (30 μg) was used for serine-phosphorylated Stat3, and the same membrane was reprobed with antibody against total Stat3.