The nonstructural maintenance of chromatin condensin I complex subunit G (NCAPG)/ Poly (ADP-ribose) polymerase 1/ E2F transcription factor 1 (E2F1) molecular axis exists in vivo. (A) Colony formation assay was performed to validate the impact of NCAPG knockdown on cell growth. (B) Intracranial in situ tumorigenesis model mice were established to evaluate the effect of NCAPG downregulation on the tumor growth of glioblastoma cells. (C) The survival of the mice was recorded and the survival curve was drawn with the Kaplan–Meier method. (D, E). Tumor tissue micro-arrays were purchased and conducted by IHC staining. The expression correlation between NCAPG and PARP1, E2F1, and its downstream targets were quantified. (F) The expression correlation between NCAPG and downstream targets of E2F1 was analyzed using the data from the TCGA and CGGA databases. (G) Gene expression profile analysis on the R2 dataset using NCAPG, E2F1, E2F1-regulated genes, and other control genes. All data are shown as the means ± SD; *P < .05, **P < .01, ***P < .001.