Homeobox protein Hox-A13 (HOXA13) is a transcription factor encoded by the HOXA13 gene, part of the HOX gene family. It plays a crucial role in limb and urogenital development by regulating gene expression during embryonic development. Mutations in HOXA13 are associated with developmental disorders such as Hand-Foot-Genital Syndrome (HFGS).Besides,Absent In Melanoma 2 (AIM2) has been identified as an interactor of HOXA13, thus a functional binding ELISA assay was conducted to detect the interaction of recombinant human HOXA13 and recombinant human AIM2. Briefly, biotin-linked HOXA13 were diluted serially in PBS, with 0.01% BSA (pH 7.4). Duplicate samples of 100μl were then transferred to AIM2-coated microtiter wells and incubated for 1h at 37℃. Wells were washed with PBST 3 times and incubation with Streptavidin-HRP for 30min, then wells were aspirated and washed 5 times. With the addition of substrate solution, wells were incubated 15-25 minutes at 37℃. Finally, add 50µl stop solution to the wells and read at 450nm immediately. The binding activity of HOXA13 and AIM2 was shown in Figure 1, the EC50 for this effect is 0.086ug/mL.