Nickols NG, et al. - In this study, investigators assessed 101 patients to recognize activated kinases as a therapeutic target in metastatic castration-resistant prostate cancer (mCRPC). They compared transcriptomic profiling of patients with mCRPC to those with localized prostate cancer and found evidence of hyperactive ERK1. Frequent amplification of members of the MAPK pathway in 32% of patients was revealed by whole genome sequencing. An association of the presence of detectable phosphorylated ERK1/2 in the primary tumor with biochemical failure after radical prostatectomy independent of clinicopathologic characteristics was noted. They suggested a viable treatment plan for metastatic prostate cancer cases could be pharmacologic targeting of the MEK/ERK pathway.