Strategy for the modification of cells with cytokines is intensively developing cancer gene therapy . Numerous studies have shown that one of the most effective therapeutic approach is to introduce the gene for interleukin-12 (IL -12) produced in the tumor microenvironment . This prevents severe toxicities caused by IL- 12 administered systemically . The most numerous research papers concern the cancer cells modified to secrete IL -12 ex vivo and used as a vaccine . It was also demonstrated high efficacy fibroblasts introduced gene for IL -12.