PLK1 and cancer: Polo‐like kinase (PLK1), a key regulatory kinase involved in mitosis and cell cycle progression,50, 51 plays an important role in tumour cell anabolism by activating the pentose phosphate pathway.52 The positive correlation of PLK1 and PKMYT1 in cancer cells may indicate a particular G2 checkpoint mechanism which synchronizes the rapid cell proliferation in accordance with maintenance of genomic stability.