SP1 and infection: TG infected with 17VP16πRR and 17VP16p1Egr1/Sp1 contained nearly 10-fold fewer clusters of infected neurons than their corresponding genomic rescues (1.75 ± 1.25 vs. 0.19 ± 0.40, p = 0.009) and (2.0 ± 1.86 vs. 0.13 ± 0.34, p = 0.0003) for 17VP16πRR and 17VP16pEgr1/Sp1, respectively, and nearly 40-fold fewer than observed with 17LpLz/VP16p2 infection.