The most logical explanation for the lack of added value is that both biomarkers are either directly (the AR pathway activity score) or indirectly (SRD5A1 gene expression) associated with activity of the AR pathway, as SRD5A1 overexpression results in increased production of androgens in prostate cancer,23 resulting in AR pathway activation. Here, SRD5A1 is linked to Familial prostate cancer.