NIMA-related kinases, or NEKs, have been identified in most eukaryotes, including humans where eleven genetically distinct proteins named NEK1 to NEK11 are expressed. Although there is no evidence that human NEKs are essential for mitotic entry, it is clear that several NEK family members have important roles in cell cycle control. In particular, NEK2, NEK6, NEK7 and NEK9 contribute to the establishment of the microtubulebased mitotic spindle, whereas NEK1, NEK10 and NEK11 have been implicated in the DNA damage response. Roles for NEKs in other aspects of mitotic progression, such as chromatin condensation, nuclear envelope breakdown, spindle assembly checkpoint signaling and cytokinesis have also been proposed. From a cancer biology perspective, overexpression of the mitotic NEKs in various tumour types suggests that they could act as important prognostic biomarkers. Furthermore, from what we currently know about their functions, inhibition of the mitotic or DDR NEKs has the potential to selectively interfere with the proliferation of cancer cells[1].