DNA microarray technology has been rapidly adopted by biomedical researchers and emerged as a promising research method in studies of human cancer. In many cases in silico data alone is not sufficient to identify a cancer predisposing gene, but when used together with other methods such as linkage analysis and functional studies this becomes a very prominent tool. This study describes various methods used in microarray technology and how the technology was utilized in studies of certain hereditary cancers together with supporting methods and technologies. Although DNA microarrays are used primarily in research, clinical applications are foreseeable and slowly emerging. This study should give more insight to the potential of microarrays as a tool for cancer research. The book should be especially useful for undergraduate or graduate students in the field of molecular biology or cancer research who wish to know more about the microarray technology and how it may be used in conjunction with other methods in genetics, or for anyone else who may be interested in microarray experiments.