Is it 100% clear cut that the infection causes the cancer, or can there be a common problem (like immune system degradation) that causes both the infection to develop (or develop easier) and the cancer the grow (which always involves failure of the immune system to kill it, if I'm not mistaken)?
Many viri are present in many human beings, but they don't develop cancer after all.
Many viri are present in many human beings, but they don't develop cancer after all.