PARP9 and cancer: As shown in Figure 4 and Table 4, several biological processes and signaling pathways were enriched in patients with high PARP9 expression, such as antigen processing and presentation, the B cell receptor signaling pathway, cytokine‐cytokine receptor interactions, Fc gamma R‐mediated phagocytosis, the JAK‐STAT signaling pathway, natural killer cell‐mediated cytotoxicity, pathways in cancer, the T‐cell receptor signaling pathway and the Toll‐like receptor signaling pathway.