he was doodling missiles. it made you what's going on. >> i think especially sort of the calm he had. that sort of tell pern't, isn't that what you want in the white house when you have these crises that are occurring? i was just really impressed by that. >> me too. >>> up next, one of the largest studies ever, they have made research in breast cancer. >> how it could lead to new treatment. you're watching "world news now." >> announcer: abc's "world news now" will continue after this from our abc stations. úd ♪ your mother your sister your wife ♪ ♪ i run for you and me my friend ♪ ♪ i run for life >>> well, it's one of the most persistent and most ruthless killers of women, and one of the biggest public health battles of our time. just last year, breast cancer killed nearly 40,000 women. >> now the results of a new study could lead to more effective treatments. but as abc's paul beban explains, it will take some time. >> the new study published in the journal "nature" is the largest of its kind eve