While the NKp30 ligand, B7-H6, is an obvious candidate (74), a very recent report identified an unanticipated ligand for NKp44 in the form of platelet-derived growth factor (PDGF)-DD (75), known for its capacity to promote of tumor cell proliferation, epithelial–mesenchymal transition, and angiogenesis. Here, NCR2 is linked to neoplasm.