The results of caspase activity assay and western blot analysis revealed that upregulating MAPK8IP1P2 increased the activity of caspase-3 or -9 and expression of pro-apoptotic proteins BAD and BAX, but reduced expression of anti-apoptotic proteins BCL2 and BCL2L1 (Figures 4C–E); conversely, silencing MAPK8IP1P2 yielded the opposite effect in thyroid cancer cells (Figures 4C–E). This evidence concerns the gene BAX and thyroid cancer.