While the DNA genome encodes all the information required for organismal survival, it must be differentially interpreted to respond to developmental and environmental cues. Thus, a major theme in cellular and molecular biology is understanding how genes are expressed from the DNA genome and how failure to properly control expression can lead to developmental defects and diseases, such as cancer. While gene expression is regulated at many levels, the fundamental first step is transcription of the DNA genome into RNA. Members of the Transcriptional Mechanism Focus Group study a wide array of processes that control transcription, including the molecular mechanisms of the polymerase enzymes, the role of transcription factors in determining what areas of the genome are expressed, and how chromatin structure influences transcription. Researchers attack these challenging and important problems using a diversity of state-of-the-art techniques, ranging from biochemistry to genetics to genomics, and in organisms, ranging from bacteria to flies to mice.