Integrin Alpha 2 (ITGa2), also known as CD49b, is one of twelve integrin family alpha subunits which is pivotal to sustain the integrity of the cytoskeletal–extracellular matrix linkage among all cell adhesion receptors. Some research had shown that ITGa2 is a cell transmembrane receptor that assists the adhesion of other several cells to the extracellular matrix. In addition, changes of ITGa2 expression affect the immune microenvironment and immunogenicity of tumors. Integrin Beta 1 (ITGb1) has been identified as an interactor of ITGa2, thus a functional binding ELISA assay was conducted to detect the interaction of recombinant mouse ITGa2 and recombinant mouse ITGb1. Briefly, ITGa2 was diluted serially in PBS with 0.01% BSA (pH 7.4). Duplicate samples of 100 μl were then transferred to ITGb1-coated microtiter wells and incubated for 1h at 37℃. Wells were washed with PBST and incubated for 1h with anti-ITGa2 pAb, then aspirated and washed 3 times. After incubation with HRP labelled secondary antibody for 1h at 37℃, wells were aspirated and washed 5 times. With the addition of substrate solution, wells were incubated 15-25 minutes at 37℃. Finally, add 50 µL stop solution to the wells and read at 450/630 nm immediately. The binding activity of recombinant mouse ITGa2 and recombinant mouse ITGb1 was shown in Figure 1, the EC50 for this effect is 0.6 ug/mL.