IL17A and astrocytoma (excluding glioblastoma): Furthermore, human astrocytoma cells were challenged with 0, 1, 10, 100, or 500 ng/ml of IL-17 for 24 h, and then the production of pro-inflammatory cytokines IL-1β, IL-6 and TNF-α (Fig. 1e,f and g) were determined by ELISA.