PTGS2 and neoplasm: IL-1 Beta in the tumour site is produced by tumour and immune cells involved in the generation of MDSC and their migration to the site of the tumour, and it induces COX-2 expression which prevents maturation and activation of antigen presenting cells at the tumour site involved in the upregulation of TNF-Alfa, MDSC immunosuppression, carcinogenesis, tumour growth, invasion and metastasis in chemically-induced tumours.