MAPK3 and oral cavity squamous cell carcinoma: Furthermore, it initiates cell proliferation in breast cancer through mTORC1-S6 kinase 1, Erk1/c-Myc axis, Hsp27, and HDAC4/5/7, and it positively regulates the immune suppressor PDL1 in oral squamous cell carcinoma (OSCC) [48,49,50,51].