Consistently, the NPAS2 gene expression level was significantly lower in cases of more aggressive forms of prostate cancer (P ≤ 0.003, Fig. 4a, b), and a low expression level of NPAS2 was associated with poor BCR-free survival in patients with prostate cancer (P = 0.002, Fig. 4c). This evidence concerns the gene BCR and Familial prostate cancer.