AGR2 and posterior cortical atrophy: AGR2 immunohistochemical (IHC) staining was performed in an independent cohort of 37 BPHs and 129 PCa clinical samples, the positive rate of AGR2 decreased as the tumor stage progressed (Fisher’s exact test, p = 0.0471, Fig. 4e), indicating that the diminished protein expression levels of AGR2 were correlated with the malignancy of tumor.