Differentially expressed complement inhibitors were validated at the protein level by immunostaining in the rat GBM cell line NS1 and patient derived GBM tissue.<h4>Results</h4>CFI, encoding factor I, was significantly overexpressed in GBM compared to non-tumoral brain, while THBD and CFH, encoding thrombomodulin and factor H, displayed moderate overexpression. Here, CFI is linked to glioblastoma.