In "Enbrel and the Autoimmune Era,"Assistant Professor Anne Pollock (http://www.theatlantic.com/technology/archive/13/06/enbrel-and-the-autoimmune-era/276911/) writes:

Enbrel illustrates a fundamental characteristic of pharmaceuticals: we are seldom more intimately connected to anything or anyone like we are to our drugs. Pills and injectable drugs are tangible objects that are external to us, but upon consumption, they transform us and even constitute us. They are simultaneously embedded in huge economic processes and literally vanishingly small-scale. Pharmaceuticals are made to cross the boundaries of the body, to calibrate or modify it. Our drugs don't simply "cure" us. They transform both our bodies and our diseases in ways we can't predict or understand by looking at either in isolation.