GLP1R and prostate cancer: Japanese researchers found that while GLP-1R was expressed in prostate cancer tissues, Exendin-4 significantly reduced the proliferation of prostate cancer cells expressing GLP-1R.[23] Nomiyama et al found by in vitro experiments that Exendin-4 significantly reduced the proliferation of the prostate cancer cell lines LNCaP, PC3, and DU145, but did not significantly inhibit the proliferation of the prostate cancer cell line ALVA-41 proliferation.