MAPK8 and cancer: The molecular mechanism of Eg5 in tumorigenesis has been investigated; it is modulated by Parkin via the Hsp70-JNK-c-Jun signaling pathway [10]; the Eg5 mutation can induce drug resistance in cancer cell lines [32]; Eg5 inhibitor causes mitotic arrest in tumor cells through activation of c-Jun NH2 kinase pathway [33].