the invention belongs to the field of genetic engineering and biotechnology , and specifically discloses a design , preparation and pharmic application of a tumor - targeted tnf - related apoptosis - inducing ligand &# 39 ; s variant . the tumor - targeted tnf - related apoptosis - inducing ligand &# 39 ; s variant is generated by a fused protein which is consisted of the ligand of cd13 , the connecting peptide and tnf - related apoptosis - inducing ligand &# 39 ; s variant , and which is by the construction of coding gene of the variant according to the technology of genetic engineering and clone , soluble recombinant expression and ordinary separation and purification . the variant , produced by the method of preparation of the tumor - targeted tnf - related apoptosis - inducing ligand &# 39 ; s variant , has favorable tumor - targeting characteristics and the significant enhancement of the anti - tumor effect . it is possible to reducing the required dosage of protein to the treatment effect , increasing the bioavailability , reducing the cost of treatment and overcome the potential toxic effects of the tnf - realated apoptosis - inducing ligand . moreover , the preparation method of the tumor targeted tnf - related apoptosis - inducing ligand &# 39 ; s variant of the present invention provides a method for producing the variant of soluble expression and high concern of polymer forms and a process of separation and purification thereof .