. >> i iteffective? let's watch. >> snap. >> these are pretty accurate. >> considering the growing popularity of these devices, it seems inevitable they will be used in ways the inventors and manufacturers could have never imagined. >>> a 4-year-old girl ballottle brain tumor with the help of a very special daughter. >> the dad said to me, will i ever get to walk my daughter at her wedding. >> right now chloe is doing well. find out what the doctors ordered now that makes this story even better. >> that's huge. >> and there's something very wrong with this festive light display. >> oh, no. >> you are kidding me. >> see how some holiday pranksters decided to deck the halls t >>> this is dr. alex levy. he's a childhood cancer specialist at the arnold palmer hospital. he put this video to tell a pretty heart wrenching story. >> on christmas eve i got called because there was a young girl 4 years old who came in to the emergency room the night before with vomiting, headaches, trouble walking. >> he's telling