HA25 is another example of acini and ducts (compare with HA18) of exocrine glands. Myoepithelial (ME) cells are specialized smooth muscle-like cells within the basement membrane of the epithelia of acini and ducts. These contractile cells facilitate movement of secretions. HA25 shows several examples of these cells in a mammary gland. They have elongated nuclei that are parallel to the basement membrane. These cells receive innervation or hormonal signals that cause them contract to help push the exocrine secretions from the gland.