It is generally considered that squamous cell cancers of the breast frequently test negative for hormone receptors.[11] Some reports have discussed how this is connected with EGFR and HER2, and suggested that EGFR and HER2 are generally considered to be important prognostic factors for breast cancer and are negatively correlated with ER.[12] It has been reported that preoperative mammograms often show tumor shadows, but spicula formation and calcification are not common.[13] Consistent with this report, the present cases exhibited tumor shadows, but they did not clearly display any spicula. The gene discussed is ESR1; the disease is breast cancer.