TTK and breast cancer: This demonstrated specific expression alternation of genes in our study, including TTK, EXO1, TICRR (TOBPPI interacting checkpoint and replication regulation) and so on, would be closely associated with BRCA1/2 mutations, providing a clue for further understanding the certain characteristic of BRCA1/2-mutant BC (for example, increased risk of distant metastasis and more aggressive nature) (Wang et al., 2018) and clarifying its pathogenesis.