AR and posterior cortical atrophy: Han et al performed transcriptomic profiling of metastatic castration resistant PCa patient specimens and patient derived xenografts and proposed three main groupings; AR high, neuroendocrine / small cell, and “mesenchymal stem cell like” and subsequently found that HER2 and HER3 (ERBB3) were key drivers of the mesenchymal stem cell like group [35].