The making of a portrait--bringing it into focus.

The data generated by DNA arrays are often described as the molecular "portrait" of a particular physiological/pathological sample. Although the emotional reactions could range from revulsion to adoration when viewing those portraits, as it might be when viewing some contemporary art, array technology has fundamentally changed the way researchers approach many biomedical questions. With its ability to monitor the expression level of tens of thousands genes simultaneously, microarray technology has been able to identify "markers" for complex diseases such as cancer. While massive amounts of work lie ahead to validate those marker genes, many researchers are turning their attentions to the low-density, focused arrays. When incorporated with current knowledge on specific biological pathways, these specially tailored macroarrays may be better fitted for purposes such as diagnosis, drug discovery and validation, and prognostic assessment of clinical treatments.