So, stick some cells in a petri dish so they swim about in e-liquid “extract” and see if the cells “die”, which they will do in pretty much any scenario.

Key points missing:
- the non-treated cells also showed signs of cell death.
- exposure was for 24/7 for up to eight weeks
- the cells used in the experiment are technically human, but you don’t have any like them in your body
- cell cultures were specifically chosen from cancerous cell lines

Finally:
Drowning near-human cells in anything will have an effect, but you cannot specifically claim that it is “cancer causing”. You can say they have similar effects as some things that cause cancer – and some things that don’t. (HNSCC), a disease for which traditional cigarette smoking is a well-established risk factor yet the potential role of e-cigs has remained entirely unexplored.