Microsoft co-founder Paul Allen is being treated for non-Hodgkin's lymphoma.

A family member says Allen was diagnosed earlier this month and is undergoing chemotherapy now.

At a Seahawks fundraiser at Lucky Strike in Bellevue, players and fans learned for the first time of the news.

"Our thoughts and prayers are with Paul and his family. He's a great guy and an asset to the city," says fan Lorin Sandretsky.

This isn't the first time Allen has been diagnosed with cancer. In 1983, he was treated for Hodgkin's disease, the same type of cancer our Bill Wixie beat this year.

Both Hodgkin's and non-Hodgkin's lymphoma are cancers of the white blood cells and can affect the lymph nodes. Non-Hodgkin's lymphoma is more common, the fifth most common cancer in the US. It's also more aggressive, but doctors say with a variety of treatments like chemo and drug immunotherapy, the prognosis is still good.

"Once patients learn about the disease and treatment we can focus on them being cured. We do quite well and the majority of patients are cured," says Dr. Stephen Petersdorf with the Cancer Care Alliance.

Symptoms of non-Hodgkin's lymphoma include night sweats, swollen lymph nodes and weight loss. Most people who get it are men in their 60's. Allen is 56 years old.

Allen's sister sent a letter to employees of his investment company "Vulcan" Monday afternoon. It says "Paul is feeling OK and remains upbeat. He continues to work and has no plans of changing his role at Vulcan, but his health does come first."