In contrast, in another C57BL/6 mouse model of melanoma based on B16F0 melanoma cell line, high level CCL21 release (~800 pg/5 × 105 cells/48 h in vitro) driven by UB promoter from melanoma enabled massive infiltration of tumors with CD4+CD25−, CD8+ T lymphocytes, and CD11c+ dendritic cells, and consequent activation of cellular and humoral immune responses sufficient for complete rejection of CCL21-positive melanomas within 3 weeks in all tumor-inoculated mice [15]. Here, CD4 is linked to melanoma.