Offermann A, Joerg V, Hupe MC, et al. - Since there is lack of biomarkers helping in the diagnosis of high-grade prostatic intraepithelial neoplasia (HGPIN) as well as its differentiation from benign glands and other glandular lesions, researchers here attempted to explore this by analyzing CDK19 expression, using immunohistochemistry, on prostate needle biopsies of 140 patients diagnosed with prostate cancer (PCa) using whole tissue sections, and compared CDK19 levels between HGPIN, PCa and adjacent benign glands. The presence of HGPIN was detected in 65.7% of biopsies and in 88% it was linked with adjacent PCa. In 82.6% of HGPIN, CDK19 overexpression was evident. CDK19-negativity or only low CDK19 expression was found in 89.3% of benign glands. Findings support CDK19 evaluation which not only facilitates precise and simplified diagnosis of HGPIN with high sensitivity and specificity but also assists the differentiation to non-neoplastic glandular changes. Taking into consideration that HGPIN diagnosis has a high clinical significance, CDK19 was recommended as a diagnostic biomarker for HGPIN.