Every disease fits in one of these categories. .
What is going on now in our time, is that scientist are trying to treat liver cancer with a virus. We are now in a position to be able to, use viruses as vectors, meaning that they are able to transmit something. An example of this is the mosquitoes that transmit the west Nile virus, they do not cause the disease, but rather they transmit it from their body to yours. Insects are vectors of germs. So now we are trying to use a certain kind of virus as a vector for some sort of a chemical substance that they are trying to put in a cell. Inside of a liver there are a mixture of cells, those that are cancerous and those that are normal. Anytime chemicals are put in the body, you want to make sure that they kill the cancer cells and leave the rest of the body alone. For example, cyanide will kill cancer cells real well, but can affect the patient. So we worry a lot about safety and side effects. This is all involved in chemotherapy, where the patient feels rotten and terrible from the side effects of the medication, but they have no alternative. We like to get around the side effects, so we try to develop a drug where we kill the cells but leave the rest of the body alone, this has yet to be developed. .
Viruses are really good at targeting a particular cell in the body, for example the flu attacks the epithelial cells of the lung and no other cell. Every kind of virus is specific for infecting a particular cell in the body. Adenovirus for example, cause the common cold. We are going to isolate this adenovirus, and treat this virus in some way so as to render it non-damaging, so that even when it enters the body it will not cause damage to us, we still need it to enter the cell that we want it to. We are then going to attach to it a drug that will kill cancer cells, so that when it enters the cancer cells, it will kill them and leave all the other cells alone.