To comprehensively characterize B-ALL-related germline NBN variants, we utilized the HEK293T Landing Pad model to examine variant function at a single cell level.31,32 First, we knocked out the endogenous NBN gene by CRISPR/Cas9 editing (hereafter, NBN−/− HEK293T LP cells). This evidence concerns the gene NBN and precursor B-cell acute lymphoblastic leukemia.