BOSTON --? Celtics guard Marcus Smart said his 63-year-old mother has been diagnosed with bone marrow cancer but that she implored him to rejoin the team for the start of the playoffs in hopes that she can watch Smart play again this season. Smart said his mother, Camellia, revealed her diagnosis when Smart visited her in Dallas last week. Smart is currently rehabbing from thumb surgery but has said he's targeting his return for a potential Game 7 in the team's first-round series against the Milwaukee Bucks. That game, if necessary, would be played on April 28. Smart's older brother, Todd, lost a long battle with cancer at the age of 33 in 2004, when Smart was just 9 years old. Smart said he does not believe a bone marrow transplant is a possibility for his mother, but he said, "She's a fighter," and, "We're trying to see what can work right now." Smart said that his mother being surrounded by family made it easier to return to Boston to watch his team...