What is protein expression?

Protein expression refers to the process by which cells synthesize proteins. In molecular biology, it's often used to produce large quantities of a specific protein of interest. This commonly involves introducing a gene encoding the protein into a host cell (e.g., bacteria, yeast, mammalian cells), and then manipulating the cell's environment to promote the transcription and translation of that gene into the desired protein. The expressed protein can then be purified and used for research, diagnostics, or therapeutic purposes.