Moreover, proteomics analysis using two-dimensional differential gel electrophoresis (2D-DIGE) and matrix-assisted laser desorption/ionization-time-of-flight-mass spectrometry (MALDI-TOF-MS) of canine mammary tumors, proposed as a model for human breast cancer, identified OAT as one of several upregulated proteins in metastatic carcinomas [68]. The gene discussed is OAT; the disease is metastatic carcinoma.