Examination of the distribution of Ago2 in various breast diseases (Figs. 8F and EV4A,B) revealed that in mammary epithelial cells of breast tissues with hyperplasia, inflammation, or fibroadenoma and cancer-adjacent breast tissues, Ago2 was primarily located in the nuclei (Figs. EV4Ai,Aii) and rarely overlapped with cytokeratin 8/18. The gene discussed is AGO2; the disease is cancer.