We designed the ten neuronal nAChR subunits gene specific primers and demonstrated for the first time that normal human mammary glands epithelial cells and mammary cancer cells express the α3, α4, α5, α6, α7, α9, α10, β2, β3, β4 neuronal nAChR subunits and examined the expression level of each subunit. Here, CHRNA4 is linked to breast cancer.