However, with the exception of certain members of species B adenoviruses, e.g. HAdV3, which have the natural ability to bind to B7.1 and B7.2 [19] and to efficiently transduce B7.1- and B7.2-expressing malignant glioma cells [20], the usage of adenoviruses in cancer gene therapy is limited, due to the low level (or absence) of expression of high affinity receptor for adenoviruses in cancer cells, or/and their poor accessibility at the cell surface. This evidence concerns the gene CD80 and malignant glioma.