later cancer biologist, andrew z hestle looks at cancer research. and thin we'll look at virtual currency. >>> this weekend on the cspan networks, friday night at 10:00 eastern on cspan, a conversation with retired justice john paul stevens, the founder and former chair of microsoft bill gates on the ebola outbreak in west africa. and the director of the museum of african art, and friday night on cspan 2, authors talk about war and the constitution. saturday night at 10:00 on become tv's afterwards, author heather cox richardson, and live at noon, on book tvs, legal affairs and editor in charge at reuters and supreme court biographer. friday at 8:00, on american history the on cspan 3, historians and authors talk about world war i, 1 one years 4r5er9. and former fbi director on catching -- the 100th anniversary of the panama canal. find our television schedule at cspan.org and let us know what you think about the programs you're watching, call us at inÑg 202-626-3400. e-mail us at comments@c-span.org. like us on facebook, follow us on twitter. >>> k