IGFBP5 and central nervous system cancer: Assessment of the prognostic value of IGFBP5 expression in glioma patients subgrouped by age (age < 60, age ≥ 60), gender (female, male), IDH mutation status (mutant, wild type), WHO grade (WHO 2, WHO 3 & WHO 4), and primary therapy outcome (PD, SD, PR, and CR) was conducted.