PTGS2 and neoplasm: In vitro studies indicate that COX2 induction may be stimulated by tumour necrosis factor-alpha stimulated protein 6 (TSG-6) released from adipose tissue derived mesenchymal stem/stromal cells (ADSCs) [113], or by cytokine interleukin-1 (IL-1) in the tumour microenvironment acting as a paracrine or autocrine factor to upregulate COX expression via canonical NF-κB signalling [114].