Analysis of molecular landscapes suggests that metastatic CRPC can be divided to several subtypes including AR-positive PCa (ARPC), AR-low PCa (ARLPC), and double (AR and NE)-negative PCs (DNPC) [52, 53], and the levels of FGFs and FGFRs transcripts are expressed at different frequencies but are significantly higher in AR-null DNPC than those in ARPC tissues, which is correlated with elevated mitogen-activated protein kinase kinase (MEK) or FGFR pathway activation in DNPC as well as ARLPC [52, 53], suggesting that the growth of PCa with loss of AR activity may be driven by FGFRs signaling. The gene discussed is WNK2; the disease is posterior cortical atrophy.