BCL2 and acute lymphoblastic leukemia: The expression of valine aminoacyl tRNA synthetase is transcriptionally upregulated by NOTCH1, a prominent oncogene in T-ALL. A genome-wide CRISPR–Cas9 loss-of-function screen performed under varying valine conditions identified several genes, such as SLC7A5 and BCL2, whose genetic deletion operated synergistically with valine restriction to decrease T-ALL growth.