TNFSF4 and neoplasm: First, OX40L treatment enhanced T cell proliferation independent of OX40 expression in ECs (Supplemental Figure 3, A–D), and correspondingly inhibited tumor growth (Figure 2, G and I) and metastasis (Figure 2, H and J) in control mice (Ox40ki/ki;Ctrl and Ox40fl/fl;Ctrl).