I'm concerned about the cancer risk, particularly, of Valcyte, which is being considered for what might or might not be HHV-6 reactivation in me (I have a high - 1:1280 - IgG titre and although I have been negative by PCR in plasma twice, I understand that doesn't necessarily rule it out). I've been on hepapressin for about a year and haven't noticed any benefit, apart from perhaps an improvement in sleep early on. I wonder if that maybe indicates I don't have an HHV-6 active infection, or perhaps I'd have noticed a change. I'm wondering if there's anything less risky than Valcyte I can try? If I was certain I had active HHV-6 I'd go for Valcyte but high titres don't seem to distinguish between Valcyte responders and non-responders in the CFS literature and I'm very unsure about Valcyte because of the potential downsides.