- The CHEK2 c.1100delC germline mutation rarely contributes to breast cancer development in the Czech Republic. Kleibl, Z., Novotny, J., Bezdickova, D., Malik, R., Kleiblova, P., Foretova, L., Petruzelka, L., Ilencikova, D., Cinek, P., Pohlreich, P. Breast Cancer Res. Treat. (2005)