CTNNB1 and Familial prostate cancer: While mutations in the Wnt pathway genes assessed are generally rare in primary prostate cancer (≤1%), inactivation mutations in APC (primary: 1.6–2.7% incidence, metastatic: 6.3–7%) and activating mutations in CTNNB1 (Catenin Beta 1) that encodes β-catenin (primary: 1.8–2.6% incidence, metastatic: 4.3–5.4%) are relatively common, particularly in metastatic prostate cancer (Table 1).