PTGS2 and chondrosarcoma: In SW1353 chondrosarcoma cells, IL-1β (interleukin-1β) induces overexpression of IL-6 (interleukin-6), PGE2 (prostaglandin E2) and Cox-2 (cyclooxygenase 2), which, in turn, activate a series of MMPs, such as MMP-1 and MMP-13 [12].