Aberrant hypermethylation in KEAP1 promoter region was the most common alteration found in nearly half of the non-small cell lung cancer (NSCLC) cases (Muscarella et al., 2011a), and has been proven to be associated with poor prognosis in various cancers including malignant glioma, breast cancer and pancreatic cancer (Muscarella et al., 2011b; Barbano et al., 2013b; Zhang et al., 2016b). Here, KEAP1 is linked to breast cancer.