TNF and infection: Further analysis has identified B-cells, macrophages, and natural killer (NK) cells as the primary immune cell subpopulations infected by H-1PV, with infection in activated cells leading to the induction of tumor necrosis factor (TNF)-alpha, interferons (IFN), and interleukins (IL) 2, 4, and 10 (Geletneky et al., 2015).