Thehuman estrogen receptor-positive breast adenocarcinoma cell line,MCF-7 (Michigan Cancer Foundation-7), was used in the present studyas we have recently reported the expression and function of LAT1 inthis cell line.21 Here, we quantified firstthe protein expression of SNAT1, SNAT2, SNAT4, and SNAT5 from theplasma membrane fractions with LC–MS/MS methods. The gene discussed is ESR1; the disease is breast adenocarcinoma.