HMEC is a cell line that was derived from the human mammary epithelial cells of a female patient who had been suffering from breast cancer. HMEC cells exhibit a cuboidal morphology and a characteristic pattern of swirls. They also exhibit adherent cultural properties, forming monolayers when grown in vitro . HMEC can be used as a transfection host to study breast cancer and oncogenesis, and an HMEC transfection reagent to transfect HMEC cells is commercially available from Altogen Biosystems . The HMEC cell line can also be used for carcinogen screening, developing therapeutics, and three dimensional culturing.