PRMT7 is a type III protein arginine methyltransferase that catalyzes monomethylation and symmetrical dimethylation of arginine residues. It mediates symmetrical dimethylation of histone H4 at arginine 3 (H4R3me2s) and small nuclear ribonucleoproteins required for snRNP assembly, while also playing roles in gene imprinting and embryonic stem cell pluripotency. PRMT7 regulates diverse cellular processes including RNA splicing and stress responses. It methylates HSP70 family proteins to modulate cellular tolerance to proteostasis perturbations 1, and controls arginine methylation of splicing factors like hnRNPA1 to influence alternative splicing patterns 2. In the immune context, PRMT7 suppresses interferon response pathways; its inhibition increases RIG-I and MDA5 expression and enhances anti-tumor T cell immunity 3. PRMT7 dysregulation is implicated in multiple cancers. In colorectal cancer, a splicing quantitative trait locus (rs61746794-T) increases expression of the PRMT7-V2 isoform, which catalyzes H4R3 and H3R2 methylation to activate oncogenic pathways (YAP, AKT, KRAS) and promote tumor growth 4. In chr16 myeloid leukemia, PRMT7 loss impairs leukemia stem cell self-renewal by reprogramming glycine metabolism 5. In smoking-associated non-small cell lung cancer, high PRMT7 expression suppresses immune surveillance and facilitates immune evasion 6. The selective PRMT7 inhibitor SGC3027 demonstrates antitumor efficacy across multiple cancer models.