Changes in expression of proteins involved in (a) regulation of cell cycle and cell death and (b) oxidative and metabolic processes of human MDAMB231 and MDAMB468 cells. Both cell lines were treated with 8 μg/mL lovastatin lactone (Lova Lac) or lovastatin acid (Lova Ac) for 48 hours. Data represent relative spot volumes (as calculated from two-dimensional gel images of whole cell extracts; data are presented as mean ± standard deviation (n = 5) *P < 0.05;**P < 0.05; ***P < 0.001). Gel spots which showed significant differences in their volume between the control and lovastatin-treated cells were cut-out, proteins were digested and analyzed using liquid chromatography (LC) mass spectrometry (MS)/MS analysis. In MDAMB231 cells they were identified as GTPase-activating protein SH3-domain-binding protein 1 (G3BP1), TNF type 1 receptor-associated protein (TRAP1) and glutathione S-transferase (GST) omega proteins (Table 1a), whereas the spot belonging to citrate lyase beta and sterol carrier protein 2 (SCP-2) originated from MDAMB468 cells (Table 1b). Cofilin1/2 was identified as upregulated in both cell lines. The image and changes as observed in MDAMB231 cells is shown.