The present disclosure describes the generation and the use of Ad variants (Ad) possessing any combination of mutations in genes that code for the hexon, penton, fiber, and non-structural proteins, where simultaneous modification of hexon and penton are made to avoid the trapping of Ad in the liver and to reduce toxicity after intravascular virus administration. Such liver de-targeted Ad can be useful tool for selective and specific gene delivery to extra-hepatic tissues and cells, including disseminated metastatic cancer cells.