CENPA and cancer: In addition, varying the expression levels of centromeric components, first and foremost CENP-A and its chaperone HJURP, has been shown to have opposite effects on cells: while downregulation promotes both cell proliferation arrest and senescence, upregulation leads to chromosome instability and cancer transformation, although via molecular mechanisms that need to be clarified; indeed, CENP expression levels could now be used as biomarkers for some types of cancers.