PIM1 has been hypothesized to amplify the growth signals from STAT3, an isoform of the signal transducers and activators of transcription (STAT) protein family, to activate transcription factor nuclear factor of activated T cells (NFAT), which in turn promotes the pro-proliferative and anti-apoptotic phenotype of PAH (Paulin et al., 2011). Here, PIM1 is linked to pulmonary arterial hypertension.