TTK and breast cancer: Inhibition of TTK has been found to suppress the proliferation of tumor cells in lung cancer, colon cancer and breast cancer.[35, 36, 37, 38, 39] Moreover, TTK inhibition could induce mitotic errors and enhance apoptosis in breast and pancreatic cancer.[36, 39] In HCC, targeted inhibition of TTK reduced tumor aggressiveness, and induced DNA damage, micronuclei formation, autophagy, and cellular senescence.[16] TTK has also been reported to be associated with drug resistance of tumor cells.