SOME AGING-RESEARCH CONUNDRUMS: “You might think that a drug which acts like COX-2 to cause more prostaglandin E2 (PGE2) production and therefore more bone healing is the ticket. But every time we hear about a drug that can reverse some metabolic change that comes with aging we have to ask why the body changed with age in the first place. The decline of COX-2 with age down-regulates stem cells to inhibit stem cell activity. Why? Just an accident of decay? Or was this selected for because older stem cells are at risk of becoming cancerous when they divide?”