Some Class 1 (bacterial-type II) L-asparaginases have been used in clinical ALL chemotherapy, including the Escherichia coli enzyme EcAII (Elspar) (Swain et al., 1993), its PEGylated version (Oncaspar) (Dinndorf et al., 2007) and an alternative bacterial enzyme from Erwinia chrysanthemi ErAII (Erwinase) (Gervais et al., 2013). This evidence concerns the gene ASPG and acute lymphoblastic leukemia.