This workflow is as follows. First, the sgRNA library was designed and cloned into a lentiviral CRISPR vector, and then the lentivirus was packaged with the sgRNA library lentiviral vector, psPAX2 and pMD2.G vectors in the HEK293T cells. Next, MOLM13 cells were infected with a low MOI (0.3) virus and these cells underwent puromycin selection. Then, the single clone was seeded in a 96-well plate. Finally, the sgRNA single clones integrated into a genome were identified by one-step RT-qPCR, Sanger sequence and Indel mutation detection.