[ejstronge]

> Also that's a pretty common misconception, cancer is pretty well defined, abnormal cell growth

I don't think cancer biologists would subscribe to this simple definition (and it's not hard to find cases of 'abnormal cell growth' that do not ultimately constitute cancer). There have been, and continue to be, publications that pose the question of what it means for a patient to have cancer (cf https://www.cell.com/fulltext/S0092-8674(11)00127-9 )

Cancers quite clearly cause different diseases - it's even the case that cancerous cells can yield distinct clinical presentations simply based on whether they are primarily found in the blood or in solid organs.

I don't think anyone would disagree that 'viral infection' is also an unhelpful description. Viruses may transiently infect host cells and die out (the common cold, for example) or permanently become part of the host genome (consider the various herpesviridae).