Unsurprisingly, health and disease have always been on the minds of humans. After all, this most fundamental yin and yang of life is without doubt one of the strongest drivers of our happiness, success, and general outlook on life. The more we learn the more we realize that our physical and mental well-being are ultimately a reflection of the myriad of biochemical, electrical, and mechanical processes chugging along in our bodies every minute, day and night. Slight derailments of some processes we might not even notice, but others, just think toothache, are annoyingly distractive, even if 99.99 percent of our physiological machinery is working just fine. No wonder that the desire to understand the connections between molecules and a happy or not so happy life have fascinated biologists for many years.

When systems biology began to gain popularity at the beginning of this century, health and disease were portrayed as prominent targets, but with a new twist: the novel promise of personalized medicine and predictive health. Building upon this promise, the director of the National Institutes of Health, and the commissioner of the US Food and Drug Administration, laid out a road map for investments in this new field of “4P medicine,” which was to become Personalized, Predictive, Preventive, Participatory. They also proposed efforts to streamline the path to new and improved treatments, which were to be custom-tailored to the individual. These treatments should dispel the old cliché of the doctor's advice to “take two pills and call me in the morning.” Instead, they portrayed a vision of science-based efforts to adjust and individualize important disease treatments according to each patient's age, metabolism, and many other personal characteristics. This vision implied that government, universities and drug companies would team up to develop new, effective drugs and diagnostics so doctors would be enabled to prescribe “the right drug at the right dose at the right time.”

The vision of predictive health goes one step further. The basic idea is quite simple, but its implementation will be time-consuming and require vast resources. In the first phase of this implementation, dedicated health centers will perform thousands of measurements on large cohorts of healthy individuals of various ages and repeat these measurements regularly over a time period of several decades. As one might expect, some of these individuals will eventually develop a serious chronic disease.