IL1B and pulmonary hypertension, primary, 1: As expected, IL-1β and NF-κB, two proinflammatory cytokines thought to be involved in many acute and chronic diseases [29, 30], were upregulated in spleens of vehicle-treated PHT rats, though IL-1β was not significantly different between PPVL-VEH and SHAM-VEH rats (p>0.05; Fig 6B).