A total of 11,911 HER2‐negative BC were included to compare the clinical characteristics and prognosis between HER2‐zero and HER2‐low BC, and 4227 of the 11,911 HER2‐negative BC were further compared to 5653 controls to investigate subtype‐specific epidemiological factors and single nucleotide polymorphisms(SNPs). This evidence concerns the gene ERBB2 and breast cancer.