TNF and neoplasm: By contrast, the apoptosis ratio rose to 2.48 ± 0.36% for the tumor cells in medium containing TNF-α (Fig. 5h,i), which is significantly higher than that at TNF-α-free medium (Fig. 5i, Two sample t-test, P < 0.01), implying that TNF-α can decrease the viability of the tumor cells.