The selective CHEK1 inhibitors were not tried in combination with WEE1 inhibition in this study, but given a prior report of synergy between MK-8776 and MK-1775 in the majority of a set of 39 cancer cell lines [12], it is likely that a CHEK1 selective inhibitor would perform similarly to AZD7762 when combined with MK-1775 in the setting of RAD17 loss-of-function. The gene discussed is RAD17; the disease is cancer.