PRMT7 is a Type III protein arginine methyltransferase that catalyzes arginine monomethylation (MMA) and symmetrical dimethylation (sDMA) with preference for MMA formation 1. It mediates symmetrical dimethylation of histone H4 at arginine-3 (H4R3me2s) and histone H3 at arginine-2 (H3R2me2s), regulating chr16-based gene expression 2. PRMT7 also catalyzes methylation of spliceosomal snRNPs (Sm D1/D3) required for snRNP assembly and methylates RNA-binding proteins like hnRNPA1, influencing alternative splicing 3. Mechanistically, PRMT7 participates in multiple regulatory pathways: NF-κB-induced PRMT7 promotes monocyte extravasation via RAP1A methylation in COPD 4, arginine methylation of HSP70 contributes to cellular stress responses 5, and loss of PRMT7 increases endogenous retroviral expression through reduced DNA methylation, enhancing anti-tumor immunity 6. PRMT7 also reprograms glycine metabolism to eliminate leukemia stem cells in CML 7. Clinically, PRMT7 dysregulation associates with colorectal and non-small cell lung cancers; high PRMT7 expression correlates with increased cancer risk through activation of YAP/AKT/KRAS pathways 28. PRMT7 inhibition via SGC3027 shows promise as a therapeutic strategy across multiple cancer types 362. Germline PRMT7 deficiency causes intellectual developmental delay and hypotonia in humans 1.