(WXYZ) -- Former Detroit Lions general manager Matt Millen is battling a rare disease called amyloidosis, according to a report from The Morning Call newspaper in Pennsylvania.
The report states that the disease has rendered Millen's heart at about 30 percent of its normal functioning capacity, and thus doctors have told him he needs a heart transplant. The report adds that Millen has been undergoing weekly chemotherapy treatments for the past eight months.
According to information from the Mayo Clinic and Cedars-Sinai Medical Center, amyloidosis occurs when abnormal proteins called amyloids, which are produced in bone marrow, build up in organs or tissue. While there is no known cure, the most common treatment is chemotherapy to stop the growth of the abnormal cells.
Millen, who has recently been working as a game analyst for the Big Ten Network, said in the report he hopes to return to the television booth this fall.
