CHEK2 and ovarian cancer: Evidence that CHK2 is degraded at the end of the DDR comes from work in the cervical cancer cell line HeLa, where CHK2 levels dropped at just 1 h after irradiation (Schwarz et al., 2003) and in the A2780 ovarian cancer cell line where it was degraded in response to cisplatin treatment (Zhang et al., 2005).