Rhein et al., (39) demonstrated that Arg-85 in NDUFS2 from human osteosarcoma cells was fully dimethylated, but its methylation was strongly reduced after prolonged NDUFAF7 knock-down (KD), indicating that NDUFAF7 is the arginine-specific MTase responsible for methylation of NDUFS2 at Arg-85 in vivo. This evidence concerns the gene NDUFS2 and osteosarcoma.