Fig. 6

Effects of tofacitinib on Janus kinase/signal transducer and activation of transcription (JAK/STAT) phosphorylation in granulocyte–macrophage colony-stimulating factor (GM-CSF)-stimulated neutrophils. Neutrophils were pretreated with or without tofacitinib for 30 min and then stimulated with GM-CSF (10 ng/mL) for 20 min. Phosphorylation of JAK2, STAT3, and STAT5 was determined by Western blotting using phospho-specific antibodies against JAK2, STAT3, and STAT5. Phosphorylation of JAK1 and JAK3 was barely detected (data not shown)