Part 2. Based on the Pulitzer Prize-winning book by Siddhartha Mukherjee, this three-night, six-hour documentary series, presented by Ken Burns, continues. If you saw yesterday’s Part 1, you’ll most likely be captivated enough to stay tuned to follow the progress of the understanding and treatment of this infuriatingly complex disease. It’s presented and structured here more like a murder mystery, with clues, dead ends, red herrings and inspired leaps of logic – and, in one sense, a murder mystery is exactly what the story of cancer is. Check local listings.