Expression of low‐moderate ASS and OTC in our 2T‐ALL patient samples is consistent with findings in T‐ALL cell lines and suggests T‐ALL could also be a suitable target for arginase therapy.28 ASS and OTC contribute to blast survival at moderately low arginine conditions, but encouragingly for clinical development of this molecule, blast expression of ASS and OTC cannot fully protect the cells from the cytotoxicity of BCT‐100 when arginine is depleted to undetectable levels. Here, OTC is linked to acute lymphoblastic leukemia.