From something as simple as a paperclip to far more complex machines such as computers, there are a wide variety of machines forming a regular part of our daily lives. None, however, come close to the complexity found in the machine that is the human being.  When you think of Microsoft, you might simply consider the various ways the company focuses on technologies related to computers. But Microsoft also plays a role in the human equation, and not just in trying to design better user interfaces and ergonomic hardware. Structural models and data filtering algorithms can also find application at a biological level, assisting us in better understanding our own selves, as well as the diseases which often impact us. To this end, David Heckerman, Distinguished Scientist in the eScience group, is one person at Microsoft working to find new ways to apply advanced technological algorithms to our own biology. David began his education with the intent of becoming a physicist, but his interests eventually led him into the medical sciences. While working on his MD at Stanford, he began looking at the problems of Artificial Intelligence. For his PhD work, he submitted an impressive construct he called the “probabilistic expert system." In fact, it was so impressive that in 1992 Microsoft hired him to build such systems for non-medical applications. David’s work at Microsoft began to lead him further and further from his original medical focus. One of his pioneering areas of study was for graphical models known as Bayesian networks, and it was while working on these models that he recognized how they could be applied to medicine and biology. Today, his efforts have allowed him to return to his medical education roots, and he is working both to design such things as a vaccine for HIV and search for genetic causes of disease.