CHEK2 and breast carcinoma: Although Cds1-Mus81S.p. interaction is conserved in human cells (CHK2-MUS81), it is unclear if CHK2 directly regulates MUS81 as in fission yeast (reviewed in [8]), although there is evidence that CHK2 up-regulates the protein level of MUS81; MUS81 in turn contributes to activation of CHK2 in Cisplatin-treated breast cancer cells (Figure 3) [84].