Updated project metadata. The plasma membrane proteome resides at the interface between the extra- and intra-cellular environment and through its various roles in signal transduction, immune recognition, nutrient transport, and cell-cell and cell-matrix interactions plays a critical role in determining the fate of a cell. The objective of this study was to characterize the cell-membrane proteome of SKBR3/HER2+ breast cancer cells by using mass spectrometry detection, to advance the understanding of biological triggers that sustain aberrant cell survival, proliferation, and development of resistance to therapeutic drugs.