CD4 and neoplasm: In the Lewis mouse model of lung cancer metastasis, tumors treated with 4B (42) and K-CRGDV-4B (43) showed a significant increase in the proportions of B lymphocytes, CD4-positive T cells, and CD8-positive T cells, and the changes in the proportions of the immune cells suggested that 4B and K-CRGDV-4B improved the tumor immune microenvironment.