CD226 and neoplasm: We identified significant gene and GO Biological Process (GOBP) pathway signatures that positively and negatively modulated NK cells’ anti-tumoral capacity, such as CD226, a known activating receptor for NK cell cytotoxicity53, and PDCD1, the Programmed Cell Death 1 gene, encodes the PD-1 protein that down-regulates NK cell anti-tumor activity54 (Figure 2a, Supplementary Materials 2).