Protein arginine methyltransferases (PRMTs) catalyze the methylation of arginine residues on both histone and non-histone substrates, orchestrating cellular processes such as transcriptional regulation, RNA splicing, signal transduction, and DNA damage response. Because dysregulated methylation reprograms epigenetic and post-transcriptional landscapes to promote malignant transformation, aberrant PRMT activity is closely associated with tumorigenesis and cancer progression. Major family members,...