PKM and breast cancer: For instance, PRMT4, alternatively known as co-activator-associated arginine methyltransferase 1 (CARM1), is overexpressed in breast cancer cells and regulates breast cancer progression and chemo-sensitivity through catalyzing the arginine methylation of multiple proteins such as pyruvate kinase M2 (PKM2) isoform, BAF155, and RNA polymerase II mediator complex subunit 12 (MED12) (Wang et al., 2014, 2015; Liu et al., 2017).