MAPK8 and cancer: Previous studies have reported that TOPK directly phosphorylates ERKs, histone H3 (Ser10), histone H2AX (Ser139), peroxiredoxin (Ser32), JNK (Thr183/Tyr185), and PRPK (Ser250), indicating that it is a promising target in cancer related to growth, DNA damage, the cell cycle, and apoptosis.