PRMT7 and breast cancer: The PRMT enzymes are classified into three groups; type 1 PRMTs (comprising PRMTs 1, 2, 3, 4, 6, and 8) mediate asymmetric dimethylation of proteins which results in ADMA release during proteolytic protein breakdown, type 2 PRMTs mediate symmetric dimethylation (i.e., SDMA formation; PRMTs 5 and 9), and type 3 PRMTs solely catalyze monomethylation of proteins (PRMT7) (for review of PRMTs, cf. [38]), the type 2 PRMTs 5 and 9 to be downregulated in most BC cell lines, and PRMT7 to be downregulated in the two triple negative BC cell lines.