We previously demonstrated that the PKCδ-mediated Ser302 phosphorylation of hnRNPK is also important in the DNA damage-induced apoptosis of U2OS osteosarcoma cells, whereas such phosphorylation is negatively regulated by nearby methylations at arginines 296 and 299 (Arg296/299), which are located in the protein-interacting region of hnRNPK [15]. Here, HNRNPK is linked to osteosarcoma.