CD8A and head and neck squamous cell carcinoma: Subsequently, these researchers also isolated EXOs through miniSEC from the plasma of HPV (+) and HPV (-) HNSCC patients, and the results showed that plasma contained similarly high levels of exosomal proteins and similarly induced apoptosis of CD8 (+) Jurkat cells or inhibited the proliferation of CD4 (+) T cells; However, only EXOs from HPV (+) tumours had T-cell stimulation [47].