PKD1L2 and breast carcinoma: rs386792906 (chr16:g.81253642 AG>TC), which showed the strongest association with MTX chemosensitivity in breast cancer xenografts, was located in intron 1 of PKD1L2. PKD1L2 is a member of the polycystin protein family, and may function as a component of cationic channel pores [46].