ASPG and acute lymphoblastic leukemia: For example, PEGylation―the covalent attachment of polyethylene glycol (PEG) chains to specific amino acid residues―has been employed to modify asparaginase, resulting in PEGylated asparaginase (pegaspargase; PEG-ASP), which demonstrates a significantly prolonged half-life and reduced immunogenicity in the treatment of acute lymphoblastic leukemia (ALL) [231,232].