dr. cathy eng, thank you very much. >> thank you so much for having me here. >> thank you. >>> coming up, true courage. against all odds these two brothers built one of the world's most successful programs to fight aids. they did it in iran. it got them sent to prison and it became a worldwide cause. we'll explain. a cnn exclusive. that's next. my name is robin. i'm a wife, i'm a mom... and chantix worked for me. it's a medication i could take and still smoke, while it built up in my system. [ male announcer ] along with support, chantix is proven to help people quit smoking. it reduces the urge to smoke. some people had changes in behavior, thinking or mood, hostility, agitation, depressed mood and suicidal thoughts or actions while taking or after stopping chantix. if you notice any of these, stop taking chantix and call your doctor right away. tell your doctor about any history of depression or other mental health problems, which could get worse while taking chantix. don't take chantix if you've had a serious allergic or skin reaction to it. if you develop these, stop taking chantix an