For instance, it has been reported that the SARS-CoV-2 M protein can exacerbate the malignant features of the MDA-MB-231 triple-negative breast cancer (TNBC) cell line, such as its migratory and metastatic potential8, while the SARS-CoV-2 spike (S) protein can increase the proliferation of estrogen receptor (ER)-positive MCF-7 cells9. The gene discussed is ESR1; the disease is triple-negative breast carcinoma.