Two-dimensional gel electrophoresis (2-DE) and two-dimensional fluorescence difference gel electrophoresis (2D-DIGE) coupled to MALDI-TOF/TOF are useful to explore BC metabolism at the proteome level by detection of changes that occur in triacylglyceride (TAG) metabolism and metabolism-associated proteins, such as glycerol-3-phosphate dehydrogenase 1 (GPD1) and monoacylglycerol lipase (MAGL) that were found as downregulated in tumor breast tissue compared to healthy tissues [115]. Here, GPD1 is linked to breast cancer.