The associations found between ERBB2 enriched–like and triple-negative subtypes with former OC use, but not with current OC use, could be explained by misclassification or by the fact that OC formulations have changed over time and their effects on breast cancer development differ.9 Our results are in line with those found with formulations using second-generation progestins; however, the lack of information on OC formulations hampered further confirmation. The gene discussed is ERBB2; the disease is breast cancer.