In a memo sent to employees, the CEO of Allen's investment firm says the 56-year-old Allen received the diagnosis this month and has begun chemotherapy. The CEO, Jody Patton, noted that doctors say Allen has a relatively common form of the disease - and that Allen survived Hodgkin's disease in the 1980s.
Patton wrote that Allen "is optimistic he can beat this, too."
Allen founded Microsoft with Bill Gates in 1975. Since leaving the company he has become a prolific investor in real estate, technology companies and sports teams. He owns football's Seattle Seahawks and basketball's Portland Trail Blazers.
