BRCA1 and breast cancer: Although there are several studies on BRCA1/2 mutations in Chinese patients with hereditary breast cancer (Kim et al., 2016; Li et al., 2019; Liang et al., 2018; Liu et al., 2017; Wang et al., 2017, 2018; Wei et al., 2018; Xie, Gou, Wang, Zhong, & Zheng, 2017), the sample sizes in many of these studies are relatively small (Liu et al., 2017; Wang et al., 2017; Xie et al., 2017).