As we evolved to become what we are today, a series of physiological systems were adapting to an ever-changing environment thereby serving the well being of the sum, us that is. Each systems vector of evolution is a sum of its reactions to stimuli constantly subjected to change by the force of time. The vectors of permanency and intensity of a change are subjected to many factors including the interaction between the system and the changing stimulus on one hand, and the interaction with the human on the other hand. This retrospectively analytic approach, when applied to diseases in medicine, entails the immune system and its response to the changes in stimuli over the last two centuries. However, unlike the history of the Second World War, the history of our immune system is not well documented. That might be due to limitations in technology, skills, and facilities back then. Add this exponential growth science underwent made what we know about the immune systems history of little use to research today. However, entali

In a recent study by Eisen et al the immunes response to mycobacteria was evaluated at high altitudes and at low altitudes. They incubated BCG (Bacillus Calmette-Geurin) for six weeks in whole blood samples from subjects before and after their ascent from low altitudes to 3400m and compared it to growth in plasma, the negative control. It was six times and a stunning twenty five times more likely for mycobacteria to grow in bloods of subjects living at high altitudes and at low altitudes respectively than it was to grow in plasma. This elicits the rapidly adapting nature of the immune system. And although these changes were reversible, over the course of the last century or so, our immune system must have drastically evolved and permanently changed. The stimuli to our immune system have drastically changed over the course of the last years through enhancements in antisepsis and sterilization, a great decrease in infectious diseases and last but not least the discovery of the antibiotic. This draws a couple of question as to what extent did these changes vary according to region? What are the implications of this regional variation in certain diseases epidemiology? And what are the insights that can be drawn about cancer and the development of the cure?