Microsoft co-founder and investor Paul Allen has died at age 65 due to complications with cancer, CNBC reports. His company, Vulcan Inc., said that he passed away Monday afternoon. Allen’s sister, Jody, called him a “a remarkable individual on every level” in a statement to CNBC. “While most knew Paul Allen as a technologist and philanthropist, for us he was a much-loved brother and uncle, and an exceptional friend. Paul's family and friends were blessed to experience his wit, warmth, his generosity and deep concern,” she wrote. “For all the demands on his schedule, there was always time for family and friends. At this time of loss and grief for us—and so many others—we are profoundly grateful for the care and concern he demonstrated every day.” The Seattle Seahawks owner announced that his non-Hodgkins’s lymphoma had returned two weeks ago after successfully battling the cancer into remission in 2009. Allen and his doctors were “optimistic” that he could beat it again, he said.