TNFRSF1A and hepatocellular carcinoma: Overall, these results clearly show that cytosolic Ca2+ participates in the process of TNFα-induced cell apoptosis through calpain/IAP/caspase3 pathway in HCC cells and demonstrate that TNFα-induced cell apoptosis is affected by both the expressions of TNFR1 and the levels of cytosolic Ca2+ in HCC cells.