SERPINE1 and pneumonia: Parapneumonic pleural effusion (PPE) is a common sequel of pneumonia where bacteria invade the pleural cavity and stimulate pleural mesothelial cells (PMCs) to induce inflammation and coagulation [1], characterized by inflammatory cytokine surge, plasminogen activator inhibitor-1 (PAI-1) overproduction, fibrin deposition and collagen accumulation that often leads to pleural loculation and fibrosis and a significant morbidity and mortality [2].