[Laboratory tests and clinical practice: from diagnosis of an inflammatory syndrome to colon cancer screening].

The general practitioner is continually faced to the greater complexity, number, variety, and costs of available laboratory tests. The challenge is to decide in each topic what is the most important within these vast data. In a deluge of correct but relatively unimportant results, answers to questions might be hidden. This article is meant to guide clinicians to select and interpret useful laboratory tests for the diagnosis of an inflammatory process and the screening of colon cancer.