Using our characterized CRC-SC panel (Supplementary Fig. S1a), we revealed that CRC-SC hypersensitive to CHK1i (SENSHIGH) display lower basal protein levels of PARP1 than CRC-SCs moderately sensitive to CHK1i (SENSMED) or innately resistant to CHK1i (innR) (Fig. 5c). Here, PARP1 is linked to colorectal carcinoma.