C1R and neoplasm: Complement activation in the TME orchestrates the recruitment of myeloid‐derived suppressor cells (MDSCs), neutrophils, and tumor‐associated macrophages (TAMs), establishing a pro‐survival milieu.[32] Analysis via the TIMER database revealed significant positive correlations between the expression of C1r or C3 and M2‐macrophage infiltration in PAAD or LUSC patients (Figure S6C, Supporting Information).