MAPK1 and breast cancer: In addition to the independent role of HPV, recent studies have found that it may co-infect with Epstein–Barr virus (EBV) to promote the occurrence and progression of CC, BC, as well as other cancers (95), and co-infection of high-risk HPV and EBV possibly plays an important role in the progression of BC through the ERK1/ERK2 and β-catenin signaling pathways (96).