Electronic cigarettes.
D006801:Humans; D009538:Nicotine / Q000008:administration & dosage* / Q000009:adverse effects; D016540:Smoking Cessation / Q000379:methods*; D000074606:Smoking Prevention; D061485:Tobacco Use Cessation Devices / Q000009:adverse effects / Q000706:statistics & numerical data
D009538:Nicotine