H2AX and breast carcinoma: Specifically, Escherichia coli (a member of the Enterobacteriaceae family) and Staphylococcus epidermidis, isolated from breast cancer patients, were shown to induce DNA double‐stranded breaks in HeLa cells using the histone‐2AX (H2AX) phosphorylation (γ‐H2AX) assay.