On the left we see the skin cancer cells, known as melanoma, building up into tumour masses on a culture plate. On the right we see the same cancer cells reverting to a more normal behaviour in the presence of a drug that blocks the actions of a retrovirus. Similar changes were seen with the seven commonest forms of cancer, including breast, colon, brain and lung, in both culture and experimental animals.
This is not a panacea for cancer, but it is an important new avenue of research that is currently being investigated.
Cancer pictures through the kind courtesy of Corrada Spadafora