Fourteen days after various gene therapy treatments, the animals were sacrificed and tumor volume was calculated according to the formula V = A x B2 (A = largest diameter; B = smallest diameter). For histopathological analysis, livers from euthanized animals of various treatment groups were collected and cut in the middle at the site of the original tumor inoculation. The tissue was then fixed in 10% buffered formalin and stained with hematoxylin and eosin for histopathological analysis.