Validation of downregulated gene expression prioritized by IPA analysis. (A) The URA network shows downregulation (green symbols) of the putative upstream regulator (FOXM1) and the downstream molecules (with associated Z-score and p-value given under each gene, for p values, E-n symbolizes E-n)) (Care4Rare Neuron Screen). Blue arrows indicate inhibition of the physiological activating relationship between FOXM1 and related genes. Only genes for which p-adj < 0.05 are included. (B–E) U87 glioblastoma cells were treated with 250 μM hydroxyurea for 0, 4, and 8 h. qRT-PCR (n = 3) was employed to determine target gene expression with geometric normalization against GAPDH and HPRT1. (B) Fork-head box M1 (FOXM1). (C) Polo-like kinase 1 (PLK1). (D) Cyclin B1 (CCNB1). (E) Centromere protein E (CENPE). Statistical significance was measured by one-way ANOVA (nonparametric) with Tukey post hoc analysis (** p < 0.01, *** p < 0.001, ns = nonsignificant).