TNFRSF4 and neoplasm: For example, OX40 (CD134/TNFRSF4) is such a cell surface-expressed marker of T-cell activation and it has been used to image the spatiotemporal dynamics of T-cell activation following in situ vaccination with CpG oligodeoxynucleotide in a dual tumor-bearing mouse model (Alam et al., 2018).