A DNA sequence encoding the extracellular domain (Met 1-Val992) of human ITGAV (P06756-1) was fused with a flag tag at the C-terminus, constructed the plasmid 1; A DNA sequence encoding the extracellular domain (Met1-Asn707) of human ITGB6 (P18564-1) was fused with a polyhistidine tag at the C-terminus, constructed the plasmid 2. The two plasmids were co-expressed and the human ITGAV&ITGB6 heterodimer was purified.