He was 65.
His family released a statement Monday evening confirming his death:
Allen had announced a relapse of non-Hodgkin lymphoma in early October. The sports world reacted to the news of his death, just weeks after his latest diagnosis:
Trent Dilfer @DilfersDimes
So sad to hear about the passing of @Seahawks owner Paul Allen. In my 4 years in Sea he treated me, my teammates & the coaches w/great honor & respect. The Hawks treat their players as well or better than any organization because of him. My prayers go out to his family.
Allen was first diagnosed with Hodgkin lymphoma in 1982 and left Microsoft in 1983, although he remained on the board until 2000 and kept his stake in the company. His treatment for the disease was successful, but he was diagnosed with and treated for non-Hodgkin lymphoma in 2009, which again went into remission.
The money he earned through his Microsoft holdings allowed him to purchase the Trail Blazers organization in 1988 and the Seahawks in 1996. During his tenure, the Blazers reached the NBA Finals twice, but they never won a title. However, they missed the playoffs only seven times in the 30 years he owned the organization.
The Seahawks won a Super Bowl, meanwhile, and reached three Super Bowls in 12 postseason appearances during his time at the helm.
Allen also served as a minority owner of the MLS' Seattle Sounders.