STAT3 and pulmonary arterial hypertension: Moreover, studies demonstrated that PIM-1 contributes to the activation of the nuclear factor of activated T cells (NFAT)/signal transducers and activators of transcription-3 (STAT3) signaling pathway (306), which is a pathway highly involved in pro-proliferative and anti-apoptotic phenotype of VSMCs in PAH (307, 308).