Unlike eccrine sweat glands, which secrete continuously, the apocrine glands secrete in periodic spurts. Two types of sweat glands can be found in humans&colon; eccrine glands and apocrine glands. They are larger than eccrine glands, but smaller than apocrine glands. Adenolipomas are lipomas associated with eccrine sweat glands. They contain many sebaceous glands, and occasionally have eccrine sweat glands. In the skin CFTR is strongly expressed in the sebaceous and eccrine sweat glands. The clear secretion produced by eccrine sweat glands is termed sweat or "sensible perspiration". Like eccrine glands, they continuously secrete a thin, watery sweat. Like sweat glands, eccrine glands allow excess water to leave the body. Dermicidin is a newly isolated antimicrobial peptide produced by the eccrine sweat glands. The duct of eccrine gland is formed by two layers of cuboidal epithelial cells. Non-primate mammals have eccrine sweat glands only on the palms and soles. Humans have the largest number of eccrine sweat glands among species. There are no specialized variants of eccrine glands. It tends to appear in areas where eccrine sweat glands are highly concentrated.