These data illustrate a new mechanism of Chk2 activity regulation and further confirm the role of CCAR2 in the DDR, suggesting for this protein an important role in genomic stability maintenance, given that the majority of mutations and chromosomal aberrations of cancer cells reside in the heterochromatic regions of the genome [42]; for this, our studies may also support the controversial hypothesis that CCAR2 could act as a tumor suppressor gene [43]. The gene discussed is CHEK2; the disease is neoplasm.