Furthermore, functional enrichment analysis showed that gene sets associated with NRG3 in LGG are mainly enriched in neuroactive ligand-receptor interaction, cell cycle, calcium signaling pathway, and cAMP signaling pathway (Figure 12), and gene sets associated with NRG1 in GBM were mainly involved in viral protein interaction with cytokine and cytokine receptor, relaxin signaling pathway, ras signaling pathway, JAK-STAT signaling pathway, and human cytomegalovirus infection and MAPK signaling pathway (Figure 13). Here, NRG1 is linked to cytomegalovirus infection.