Indeed, type II L-asparaginases from E. coli and E. chrysanthemi (ErAII), the only two L-asparaginases with clinical interest for the treatment of acute lymphoblastic leukemia [13], are endowed with glutaminase activity that is 0.065% [14] and 1.5% [15], respectively, of L-asparaginase activity. The gene discussed is ASPG; the disease is acute lymphoblastic leukemia.