Interestingly, although CRISPR screening data from DepMap as well as our own screens indicate that all liver cancer cell lines have a dependency on ATR and CHK1, only a subset of these cell lines were responded to ATR or CHK1 inhibitors, presumably due to the discrepancy between complete CRISPR gene knockout and partial small-molecule protein inhibition [54]. This evidence concerns the gene CHEK1 and liver cancer.