Interestingly, GS treatment also induced a significant shift in the Bax/Bcl2 ratio within 36 h of GS treatment in SCC4 cells (Figure 3A(iv-v, xii), while it did not show marked effect on expression of Bak at the indicated time points (Figure 3A(vii), suggesting GS-induced apoptosis in head and neck cancer cells involves the intrinsic mitochondrial pathway. This evidence concerns the gene BCL2 and head and neck cancer.