PTGS2 and osteoarthritis: This finding is consistent with previous reports showing increased translation of IL-1β-induced COX-2 mRNA by TIA-1 depletion in human osteoarthritis chondrocytes [28] and increased COX-2 protein expression, but not COX-2 transcription or mRNA turnover in TIA-1 null macrophages [15] and fibroblasts [17].