PCSK6 and prostate cancer: The decreased cell proliferation rate and increased in cell quiescence along with the induction of apoptosis in tumors of treated animals is consistent with data obtained from in vitro cell cycle assay of LNCaP cells treated with peptide Ac-[DLeu]LLLRVK-Amba (Figure 1B), indicating that the molecular effects of this peptide on LNCaP cells in vitro are preserved in vivo. The far-reaching effects that result from PACE4 inhibition are consistent with the role of PACE4 as a hub protein for the activation of cancer promoting factors in prostate cancer.