TNF and cancer: Results showed that M1 macrophages-contained hydrogels could significantly activate caspase-3-induced apoptosis in HCC cancer cells, which was also contributed by upregulated nitrite and tumor necrosis factor-alpha (TNF-α) in loaded macrophages.378 Besides encapsulating immune cells, immune cell-regulated drugs were also entrapped and delivered by hydrogels for activating immune responses against tumor.