TKT and glioblastoma: Intratumoral expression of Ad-hsFlt3L recruits dendritic cells into the brain parenchyma [11], improving tumor antigen presentation, while Ad-TK exerts a cytotoxic effect exclusively in proliferating GBM cells in the presence of ganciclovir (GCV), leading to the release of tumor antigens and inflammatory molecules from dying tumor cells [7], [8], [10].