C3 and cancer: In addition, cancer-cell-intrinsic inflammatory tumor subclusters also showed an upregulation of C1R (log2FC = 0.86), C1S (log2FC = 0.46), and C3 (log2FC = 0.48), while the corresponding macrophages showed an upregulation of C1q genes (C1QA, C1QB, C1QC).