In monocytes with internalized TNFR1, as compared to cells which had not internalized their TNFR1, the cleavage of caspase-8 was significantly more prominent in PBMO (p < 0.05 vs. CBMO; Fig 4A right panel), suggesting that infection-induced internalization of TNFR1 initiates caspase-8 activation. This evidence concerns the gene TNFRSF1A and infection.