This is an interesting study, exploring the hypothesis that people with GCA have an overactive, "youthful" ,immune system for their age. They found a similar type of immune system in people who made it past 100 years old. My father had PMR and GCA. These were the only serious health problems that he had until shortly before his death at 103. At his 100th birthday party people commented that he looked like he was in his 80's. Apparently an overactive immune system might keep cancer and infections at bay, but put you at risk for autoimmune diseases. If you can make it through PMR and GCA without the side effects of the drugs killing you, you MIGHT have a long, fairly healthy life!