Sugimura et al. showed that switching from a GnRH agonist to an antagonist (degarelix) was associated with a delay in tumor progression in a case of CRPC [278]; moreover, a recent systematic meta-analysis has pointed out that treatment with degarelix after failure of a GnRH agonist is associated with decreased or stable PSA levels in patients progressing to the CRPC phase [279]. The gene discussed is KLK3; the disease is neoplasm.