system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How does tobacco cause cancer?
gpt
Several ways. Nicotine speeds up cell growth, and decreases tumour suppressant chemicals in the body. Then you have all the other stuff they add to the tobacco to control burn rate and so on, like acetone, formaldehyde, lead, arsenic, ammonia, hydrogen cyanide, and carbon monoxide, none of which are good.