Compared with the control group, the expression level of Bax and Bcl-XL in the SCCHN group was upregulated markedly while the expression of Bcl-2 remained unchanged [55], suggesting that the mitochondria-mediated intrinsic apoptosis pathway may participate in SCCHN CD8+ T cell death in the peripheral blood. The gene discussed is BAX; the disease is head and neck squamous cell carcinoma.