GART and breast cancer: In parallel, because glutamine is one of the upstream substrates of GART in the de novo purine biosynthetic pathway (34), we next evaluated if glutamine content was upregulated in the same tumor types by inspecting its abundance both in the breast tumors analyzed in the Breast Cancer proteome, proteogenomic and metabolomics landscape (https://www.breastcancerlandscape.org/) (7) and in the BC cell lines profiled in DepMap portal (https://depmap.org/portal).