Since p100 mRNA expression is significantly elevated by 6 h.p.i. and p52 was also shown to appear by this time, yet IκBα mRNA was not significantly elevated until 12 h.p.i., these data show that p100 processing (and thereby activation of the noncanonical pathway) precedes activation of the canonical pathway during RVFV MP12 infection. This evidence concerns the gene NFKBIA and infection.