We assayed the expression level of Prkcb mRNA in both cellular compartments by quantitative real-time PCR (qRT-PCR), and observed a significant decrease in Prkcb expression in mammary epithelial cells derived from PyMT tumors (Figure 6A), possibly indicating that epithelial PKCβ is tumor suppressive during PyMT-driven tumor formation. This evidence concerns the gene PRKCB and neoplasm.