Triple-negative breast cancer (TNBC) is an aggressive subtype of breast cancer with very limited therapeutic options. We have recently shown that the combined inhibition of EGFR and ROCK in TNBC cells results in cell cycle arrest and ultimately cell death. However, the underlying mechanisms by which co-inhibition of EGFR and ROCK induces cell death remain unclear. To investigate the synergistic effect of the combination treatment on TNBC cells, in the present study we applied a mass spectrometry-based proteomic approach to identify proteins altered upon single and combination treatments.