CHEK2 and complete blood cell count: As a BC-sensitive factor, CHEK2 is interconnected with DNA damage, replication checkpoint feedback, higher-grade malignancies, and bilateral disease [75].Czech individuals with FBC have a recurrent CHEK2 gene variant, c.1009 − 118_1009-87delinsC, which disrupts pre-mRNA splicing and increases the risk of HBC [79].