Microsoft co-founder Paul Allen says blood cancer has returned

Oct. 2 (UPI) -- Microsoft co-founder Paul Allen said he's battling cancer again.

The billionaire owner of the NFL's Seattle Seahawks and NBA's Portland Trail Blazers said in a blog post Monday he's been re-diagnosed with non-Hodgkin lymphoma. Allen has previously fought the blood cancer, which had been in remission for most of the past decade.

"My team of doctors has begun treatment of the disease and I plan of fighting this aggressively," Allen wrote. "A lot has happened in medicine since I overcame this disease."

Non-Hodgkin lymphoma is a blood cancer that develops from lymphocytes, a type of white blood cell.

"I am very grateful for the support I've received from my family and friends. And I've appreciated the support of everyone on the teams and in the broader community in the past and count on that support now as I fight this challenge."

Allen said he will stay involved with his investment firm, Vulcan, his non-profit research institutes and his football and basketball franchises.

"I have confidence in the leadership teams to manage their ongoing operations during my treatment," he wrote.

Allen founded Microsoft in 1975 with Bill Gates and left the company 1983 when he was first diagnosed.