So, we evaluated the in-vitro antitumor activity of the recombinant L- asparaginase produced by E. coli BL21 (DE3)-pET22b(+)-ASP in comparison to the marketed L-asparaginase on leukemia cells K-562 and liver cancer cells Hep-G2 using the MTT assay. Here, ASPG is linked to leukemia.