NCR2 and cancer: In contrast to evoking NK cell anti-tumor functions through PDGF-DD binding to NKp44 (41), PDGF-DD (encoded by PDGFD) binding to PDGFR-β (encoded by PDGFRB) induces pro-tumorigenic signaling pathways that are detrimental for cancer patient survival (42, 47, 96, 97).