C3 and glioblastoma: Consistent with elevated KYNU expression in GBM (Figure 1A), the complement components C3 (mean difference = 1.440, 95% CI = 0.937 to 1.886), C3AR1 (mean difference = 1.664, 95% CI = 1.333 to 2.025), and C5AR1 (mean difference = 2.337, 95% CI = 1.441 to 3.255), were significantly upregulated in GBM tissues (Figure 2J–L).