Rhabdoid cells express vimentin, epithelial membrane antigen, and smooth muscle actin.

They are also able to remodel and contract collagen and were induced to express muscle actin.

Immunostains for smooth muscle actin and cyclin D1 are characteristically positive.

Antibodies to muscle actin were also searched for by counterimmunoelectrophoresis using rabbit muscle actin as antigen.

SMA, smooth muscle actin.

Myofibroblasts can contract by using smooth muscle type actin-myosin complex, rich in a form of actin called alpha-smooth muscle actin.

Basaloid or myoepithelial cells: positive with S100 protein, muscle specific actin, calponin and p63.

These may be positive for alpha smooth muscle actin and can contract and expel the secretions of exocrine glands.

The binding of the myosin heads to the muscle actin is a highly regulated process.

They may also be positive with vimentin, smooth muscle actin, and Leu-7.