For example, TPMT genotyping prior to thiopurine treatment in pediatric ALL was found to have a favorable cost-effectiveness ratio in Europe but not in the United Kingdom , 36-37, whereas systematic analyses of PGx testing for thiopurines/TPMT revealed either inconclusive evidence 29 or cost-savings only when the data were analyzed assuming genotyping results were available at no extra cost 30. Here, TPMT is linked to acute lymphoblastic leukemia.