PTGS2 and neoplasm: In particulate matter (PM)-induced HaCaT, RSV reduced PM-induced expression of cyclooxygenase-2 (COX-2)/prostaglandin E2 (PGE2) and pro-inflammatory cytokines, including matrix metalloproteinase (MMP)-1, MMP-9 and interleukin-8 (IL-8), to promote skin injury repair with anti-inflammatory and antioxidant properties [41].