CD28 and neoplasm: We next performed cell–cell interaction analysis and identified putative ligand–receptor interactions between B cells and tumor cells, which included genes for co-stimulatory interaction partners such as CD70–CD27, CD40LG–CD40, CD58–CD2 and CD28–CD86, which are known to promote T cell activation and B cell recruitment interaction, CXCL13–CXCR5 supporting lymphoid structure formation (Fig. 8a).