This week, Science and its companion online Signal Transduction Knowledge Environment (STKE) once again throw the spotlight on STKE's expanding collection of freely accessible Connections Maps -- interactive graphical renderings of important signaling pathways, linked to relevant literature, citations, data, and background information. In a special issue, Science presents seven Viewpoint articles, written by the authorities who have crafted and maintain twelve of the online Connections Maps, that provide a look at the biological and medical insights that could flow from a better understanding of these complex networks. Links accompanying each article take you directly to the relevant Connections Maps themselves.