NCR1 and neoplasm: Viral infection of NK cells induces the expression of natural cytotoxicity receptors (NCRs), such as NKp46, NKp44 [a HLA-DP401 ligand, which is also associated with tumor recognition (Odunsi et al., 2007; Straetemans et al., 2012; Laheurte et al., 2016; Lu et al., 2017; Niehrs et al., 2019)] and NKp30 as well as the NKG2D receptor, which binds to the non-classical HLA class I-associated molecules MICA/B on tumor cells (Cantoni et al., 2015).