Three scientists were awarded the 2002 Nobel Prize in Physiology of Medicine for discoveries concerning the genetic regulation of organ development and programmed cell death. The laureates have established the nematode Caenorhabditis elegans as an experimental model, mapped the invariant cell lineage, identified key genes regulating organ development and programmed cell death and shown that corresponding genes exist in higher species, including man. These discoveries are of primary importance for understanding the pathogensis of various of human diseases.