CHEK1 and prostate cancer: Prexasertib (LY2606368) was developed by Eli Lilly as a Chk1/2 inhibitor with an IC50 of 8 nM for Chk2 and has been used in phase 2 clinical trials in prostate cancer (NCT02407054) and in 18 other studies that include solid tumors and blood cancers (e.g., NCT03057145, NCT02555644, and NCT03735446).