ERBB2 and posterior cortical atrophy: We and others have demonstrated that PCa is often associated with an increase in the activation of receptor tyrosine kinases (RTK) of the epidermal growth factor receptor (EGFR) family, including EGFR, HER2/ErbB2 and HER3/ErbB3 (HER4/ErbB4 is rarely expressed in PCa) [12, 13].