ISG15 and infection: Consistent with the notion that RIPK3-mediated signalling might evoke a dysregulated type 1 interferon response, we detected a change in the expression patterns of the Interferone Regulated Genes (ISGs) Irf7, Il6 and Isg15 early after infection (day 14), as well as in the pattern of circulating serum cytokines in RIPK3-deficient animals both at early (day 8) and later (day 105) time points.