CD4 and cancer: B cells were mainly enriched in normal tissues, while the number of B cells reduced significantly in liver metastases (P < 0.001), indicating human immunity defects in liver metastases; primary tumor had the most cancer associated fibroblasts compared to normal and metastatic samples (P = 0.001, P = 0.015); CD4+ T cells, CD8+ T cells and endothelial cells were significantly decreased in liver metastasis than in normal tissues or primary tumors (p < 0.001), while macrophages increased significantly in liver metastasis (p < 0.001) (Fig. 6B).