GO:0010468:   regulation of gene expression
Any process that modulates the frequency, rate or extent of gene expression. Gene expression is the process in which a gene"s coding sequence is converted into a mature gene product or products (proteins or RNA). This includes the production of an RNA transcript as well as any processing to produce a mature RNA product or an mRNA or circRNA (for protein-coding genes) and the translation of that mRNA or circRNA into protein. Protein maturation is included when required to form an active form of a product from an inactive precursor form.