ERBB2 and neoplasm: To study whether MED1 overexpression affects tumor cell EMT (Thiery and Sleeman, 2006; Kalluri and Weinberg, 2009), we performed real-time PCR and found the expression of several EMT-related genes, including twist, snail, and slug, were upregulated in the MMTV-HER2/MMTV-MED1 tumors (Figure 3G).