CYP2C9 was reported to catalyze the production of 11,12-EET, increase the expression of COX-2 [48] in endothelial cells, and show anti-fibrotic effects by promoting the survival of epithelial cells and the death of fibroblasts/myofibroblasts in IPF, suggesting that CYP2C9 may be involved in the pathogenesis of PF [49]. The gene discussed is CYP2C9; the disease is pemphigus foliaceus.