CD4 and osteosarcoma: (92) found a significant increase in CD4+ and CD8+ T cells and a decrease in MDSCs and Tregs in the microenvironment of osteosarcoma syngeneic mouse tumor models, which responded well to the combination of targeting angiogenesis L19 tumor necrosis factor alpha (L19mTNF-α; L), melphalan, and gemcitabine.