Essential proteins frequently overexpressed in cancer cells include PARP, DNA-PKcs, BRCA1/2, ATM, ATR, and Chk1/2 (Kim et al., 2020; Okabe et al., 2023; Yang et al., 2020; Jin et al., 2022; Savva et al., 2019; Obata et al., 2023; Dilmac and Ozpolat, 2023; Tang et al., 2024; Gralewska et al., 2020). This evidence concerns the gene CHEK1 and cancer.