To exclude the contribution of suboptimal pharmacokinetics of NCT-503 to the lack of the therapeutic activity in the BL xenograft model, we next inoculated mice with NAMALWA cells with CRISPR/Cas9-mediated PHGDH knockout and compared the growth of the obtained tumors to those with unaffected PHGDH expression. This evidence concerns the gene PHGDH and Burkitt lymphoma.