ESR2 and breast cancer: To study the role of the five assorted genes, PTGS2/ESR2/EGFR/JUN/and MMP2, in breast cancer tumorigenesis, we explored the expression profile of these genes individually in breast cancer tissues at the protein level through THE HUMAN PROTEIN ATLAS online tool.42 This database provides information about the expression level of the protein-coding genes from 20 different types of human cancers, including breast cancer, with different histopathological classifications, using the analysis of Immunohistochemistry (IHC).