Cis-acting regulatory element: a DNA sequence that is usually located near and controls the expression of a gene or genes. Includes elements such as enhancers (e.g., $UAS_{GAL}$), repressors (e.g., $URS_{GAL}$), operators (e.g., $lacO$), promoters (e.g., the $GAL4$ promoter that contains the TATA box; another example is $lacP$ in //E. coli//), etc.