AKT1 and head and neck squamous cell carcinoma: Shinya Sento et al. proved that HNSCC-derived EXOs can self-absorb or be absorbed by surrounding tumour cells and then promote cell proliferation and invasion by activating the protein kinase B (AKT), mitogen-activated protein kinase(MAPK) / extracellular signal-regulated kinase (ERK), and c-Jun N-terminal kinases (JNK) signalling pathways [53].