Beta-actin (ACTB/ACTB) is one of six different actin isoforms in humans. Actins are highly conserved proteins that are involved in cell motility, structure and integrity. Beta actin is a major constituent of the contractile apparatus and one of the two nonmuscle cytoskeletal actins. Beta-actin gene is stably and constitutively expressed at high levels in most tissues and cells, and commonly used as a loading control for western blot and as a control for qPCR.