getting more irregular, evolving, you really got to worry. >> i can ask about that. sometimes you have a mole. sometimes they take different shapes. you can't ignore that i want to get back to dr. siegel's point. asking this point dr. samadi. we talk about sunscreen. if i put on sunscreen with a certain spf, will it prevent me from gigabyte at this point? >> certainly you should wear the sunscreen. we just talked about you getting vitamin d. if you're exposed out there for 20 minutes twice a week you would get enough vitamin d. but you should wear your sunscreen now. white shirt or you're wearing a beautiful white dress, that's a spf 4 by itself. so if you don't have any sunscreen, even wearing a white t-shirt protects you at spf 4. you would go to the market and see spf 15 versus 30. it does not mean it will cover you double the amount of protection. spf 30 covers about 97%. 15 will cover you 92%. so in my book, there is no reason to buy anything more than