MLKL and infection: Necroptosis: Uninfected HOS and A549 cells had very low phosphorylation of RIP3 and if anything there was a decrease in p-RIP3 overtime in HOS and A549 cells upon SFV4 infection (Fig. 2g–i, Supplementary Fig. 3, a, b) and no increase in p-MLKL after SFV4 infection in either HOS or A549 compared to their control (Fig. 2j).