Ready-to-use ELISA kits are available for the detection of homeo box D13, an alias of the protein, homeobox D13. The official gene symbol is HOXD13. The protein, with a mass of 36.1 kDa and length of 343 residues, is reported to be nuclear. It is a member of the Abd-B homeobox family and may be known by other names, including: BDSD, BDE, homeobox protein Hox-4I, homeo box D13, homeo box 4I, and homeobox protein Hox-D13, and SPD.