Background The human complement system plays an essential role in innate immunity in the tumor microenvironment. However, the exact function of complement in gliomas progress is still ambivalent and unclear. Methods A total of 194 complement genes were included in our study to build a risk score model based on the CGGA database and was verified by the validation database and our sequencing data. Kaplan-Meier analysis was used to compare survival differences between groups. CIBERSORT and

more »

... algorithms were applied to explore immune infiltrates in the tumor microenvironment. The biological processes and functions were identified by GO and KEGG analysis. Results We build a risk score model using univariate and multivariate Cox regression analysis based on the CGGA database and verified in the TCGA database. Patients with gliomas in the low-risk group have a better prognosis and were associated with low grade, 1p19q codeletion, IDH mutant status, MGMT promoter methylation. In addition, the low-risk group is prone to have more infiltration of CD4 naive T cells and monocytes. Patients with gliomas in the low-risk group exhibit temozolomide sensitivity. Moreover, we explored several vital pathways that were associated with complement genes in this study. Conclusion Complement-related gene signature can predict the malignancy and outcome of patients with gliomas and was related to temozolomide sensitivity, which might act as a promising target for gliomas therapy in the future.