As most CSCs from patients with CRC require the key RS response mediator checkpoint kinase 1 (CHEK1, best known as CHK1) for survival7, Manic and collaborators harnessed prolonged, repeated exposure to a pharmacological CHK1 inhibitor (CHK1i) to relieve CSCs from RS response addition, ultimately obtaining CHK1i-resistant CSCs. The gene discussed is CHEK1; the disease is colorectal carcinoma.