RIPK1 and infection: In another study, an enhanced viral load in Ripk3−/− mouse brain following infection with ZIKV was attributed to impaired activation of the nucleotide sensor ZBP1 and downstream RIPK1 and RIPK3 signaling to restrict viral replication, due to changes in cellular metabolism due to the upregulation of an enzyme, IRG1, and production of the metabolite itaconate (84).