Kimura et al. reported that the activity of nuclear factor kB (NF-kB), a transcription factor which regulates proinflammatory cytokines, increased in the MCT rat model of PAH, while intratracheal instillation of NF-kB decoy oligonucleotides-NPs (PEG-PLGA) attenuated the development of MCT-induced PAH in rats [23]. This evidence concerns the gene NFKB1 and pulmonary arterial hypertension.