However, it was recently demonstrated that NKp44 engagement by dimers of platelet derived growth factor (PDGF-DD), another physiologic ligand, enhanced the secretion of IFN-α induced by a TLR9 ligand (157) suggesting that NKp44 possibly works as a dual function receptor also in pDCs and that its inhibitory role needs to be re-assessed in each specific tumor context. This evidence concerns the gene TLR9 and neoplasm.