In molecular biology, an inducer's a molecule that starts gene expression. For a gene to be expressed, its DNA sequence must be copied (in a process known as transcription) to make a smaller, mobile molecule called messenger RNA (mRNA), which carries the instructions for making a protein to the site where the protein's manufactured (in a process known as translation). Many different types of proteins can affect the level of gene expression by promoting or preventing transcription. In prokaryotes… (More on Inducer)