I have a friend who participated in the JHU study. Unfortunately, he wasn't able to quit smoking and is continuing his two-pack-a-day routine. From what I gathe

I have a friend who participated in the JHU study. Unfortunately, he wasn't able to quit smoking and is continuing his two-pack-a-day routine. From what I gather though, 3+ years on, the majority of other participants in his study have managed to quit entirely. Shame he wasn't able to do the same.