It prevents entry into mitosis when cellular DNA is damaged, and frequently expressed at high levels in various cancer types.23 Inhibition of WEE1 has shown promise as an antitumor strategy, especially in cancers with inactivated TP53.24 The WEE1 inhibitor AZD1775 has been analyzed in a phase Ib trial for patients with advanced solid tumors, including SCLC (NCT02482311).43 Here, TP53 is linked to cancer.