Intra-tumoural injection of a tumour-selective oncolytic double-deleted vaccinia virus (vvDD) armed with the chemokine CXCL-11 was found to enhance the recruitment of tumour-specific CD8+ effector T-cells into the TME in a murine AB12 mesothelioma model, leading to locally elevated levels of granzyme B and reduced expression of several suppressive molecules including TGF-β, cyclooxygenase 2 (COX2) and CCL-22. This evidence concerns the gene PTGS2 and mesothelioma.