C4A and metastatic neoplasm: Furthermore, when analyzing the correlation between infiltration abundance and clinical features, we found that the infiltrating density of MΦ-C4 was higher in GEP class 2 tumors (P = 0.024) than in GEP class 1 tumors (Fig. 3c, Supplementary Fig. 3a) and MΦ-C4 infiltrated more in metastatic tumors (Supplementary Fig. 3b).