IGF1 and glioblastoma: By further using the Cox proportional hazards model with clinical variables for GBM patients of TCGA cohort, the high-IGF-1/low-miR-181d status, G-CIMP phenotype, age, and Karnofsky performance score were independently correlated with overall survival, while gender was not associated with overall survival (hazard ratio (HR) = 1.435, p = 0.022) (Table 2).