Transcriptional regulatory elements such as promoters, enhancers, silencers, and insulators help control gene expression. Promoters initiate transcription and contain core and proximal elements. Enhancers can activate transcription from farther distances by binding activator proteins. Silencers negatively regulate genes by binding repressor proteins. Insulators block interactions between genes to prevent neighboring transcriptional effects. These cis-acting elements help precisely regulate protein levels through transcriptional mechanisms.