Ubiquitin-proteasome is involved in prostate cancer in various ways by modulating prostate cancer-related genes/proteins such as androgen receptor (Li et al., 2014), heat shock protein (HSP) 90 (Chen et al., 2016), cyclin-dependent kinase inhibitor p27, cyclin D1 (Zheng et al., 2016), and PTEN (Yang et al., 2017). Here, CCND1 is linked to prostate cancer.