On The Pump Handle, Liz Borkowski surveys a new report on chronic illness released by the Institute of Medicine. Borkowski writes, "diabetes and heart disease are what leap to my mind—in part because they're so tied to the lifestyle factors of smoking, inadequate exercise, and poor nutrition, and in part because they cost our health system so much money." But other physical (and mental) afflictions beleaguer tens of millions of Americans (116 million of which, for example, suffer from chronic pain). In total, the IoM report "highlights nine 'clinical clusters' that together 'encompass and flesh out the range of key issues that affect the quality of life of patients with the full spectrum of chronic illnesses,'" and Borkowski summarizes each of them. She also notes that "more than one-fourth of the US population has two or more chronic conditions and the prevalence of multiple chronic conditions increases with age." Managing and perhaps someday preventing chronic illness will make for a happier future, but each disease presents its own complex dynamics. On ERV, Abbie Smith explains that cancer can develop resistance to treatment just like bacteria and viruses do. She writes, "Because of the genomic diversity of the population of tumor/bacteria/virus, when you apply the treatment, there is a small sub-population that is resistant to the treatment."