To further validate the clinical relevance of noncanonical AR activity in the development of ENZ resistance, we performed IHC to examine protein expression of the AR-CXXC5-ID1 axis in a group of patients diagnosed with hormone naive PCa (n = 24), CRPC (n = 16), or ENZ-R PCa (n = 13). Here, ID1 is linked to posterior cortical atrophy.