A genetically modified mesenchymal stem cell (MSC) and medical use thereof in the treatment of tumors, the MSC including one or more exogenous nucleic acid molecule(s), wherein the exogenous nucleic acid molecule(s) include a region encoding one or more immune response-stimulating or immune response-modulating cytokine(s) operably linked to a promoter or promoter/enhancer combination. The invention encompasses the use of the cells in modulating the tumor microenvironment in order to attract immune effector cells and facilitate their activation and/or adoption of a memory phenotype. One aspect of the invention relates to the use of the cells in anti-tumor treatment including combined administration of the mesenchymal stem cells with anti-tumor immunotherapies, such as checkpoint inhibitors, immune cells, for example T cells, such as T cells with artificial T cell receptors, for example a chimeric antigen receptor (CAR-Ts) or exogenous T-Cell Receptor (TCR) transduced cells, NK cells or macrophages/monocytes, or a cancer vaccine.
