The upregulation of PRMT4, PRMT5, PRMT7, and hnRNPA1 arginine methylation, as well as the altered alternative splicing in clinical BRCA, CRC, and PC tissue samples, prompted us to examine whether these three PRMTs and hnRNPA1 methylation are functionally important in regulating the growth of these cancer cells. The gene discussed is HNRNPA1; the disease is cancer.