Mom Sara (Cameron Diaz) is fully focused on saving Kate's life, even if it means using youngest daughter Anna (Abigail Breslin), who was genetically engineered to be a donor match with Kate, as a source of spare parts.

Director Nick Cassavetes, who previously honed his weepy chops on The Notebook, occasionally lets the film get too graphic, time-jumping to many of Kate's toughest, lowest, vomit-filled experiences.

But the film also shows the effect Kate's cancer has on the Fitzgerald family. Eventually, the constant surgeries wear down Anna and she hires a lawyer (Alec Baldwin) to gain medical emancipation from her parents. The movie never becomes a courtroom drama, though; it's just another member of the Fitzgerald family reaching their breaking point.

With its interwoven flashbacks and family voiceovers, the structure often threatens to derail the film, but My Sister's Keeper survives thanks to strong performances from the entire cast, especially Vassilieva, who's mostly forced to act while hooked up to tubes.

The performances just read true, which is enough to make the tears, manipulative as they may be, as genuine as they get.