For example, prostate cancer Phase IB/II trials are ongoing for the CDK4/6 inhibitors ribociclib (ClinicalTrials.gov identifier: NCT02555189, NCT02494921) and palbociclib (NCT02905318, NCT02059213), and the CHEK1 inhibitor LY2606368 (NCT02203513). Here, CHEK1 is linked to prostate cancer.