CHEK1 and cancer: Among members of the FOX transcriptional family, FOXO proteins are strongly implicated in aging, although FOXM1, an antagonist of FOXOs, is reported to serve as a master driver of the cell cycle and cell proliferation.42 While constitutively FOXM1-expressing mice exhibit a cancer-prone phenotype,40 unbiased screening via genome-wide CRISPR-Cas9 identified FOXM1 as an apoptosis driver under the inhibition of Chk1,62 indicating its double-edged sword behavior in cancers.