By integrating experimental data with bioinformatic analyses of published single-cell transcriptome and TCGA databases, we demonstrated that TNFSF15 acts as an immunostimulatory factor that promotes the production of proinflammatory and cytotoxic factors in CAR T cells, possibly through the NF-κB pathway, leading to enhanced tumor killing (Fig. 6J). Here, TNFSF15 is linked to neoplasm.