CARM1 and pachyonychia congenita: To examine whether the expression of PRMT4, 5, and 7, the methylation of hnRNPA1, or the alternative splicing events they regulate are altered in cancers, we first examined the expression of PRMT4, 5, and 7 in clinical tissue samples from several types of cancers, including breast cancer (BRCA), colorectal cancer (CRC), and prostate cancer (PC).