Anti-human NKX3.1 is the IgG fraction from rabbit anti-sera generated by immunizing the animals with purified recombinant human NKX3.1 protein. The immunogen corresponds to the amino-terminal 153 amino acids of the human protein (1) . The IgG fraction was prepared by Protein A affinity chromatography. NKX3.1 is located on human chromosome 8p21.21. It is an ­androgen-­regulated homeodomain gene with the expression of the NKX3.1 protein ­predominantly localized to prostate epithelial cells (23) . Mouse nkx3.1 is an androgen-regulated homeodomain gene with the expression of Nkx3.1 protein predominantly localized to the prostate epithelial cells (5) . Anti-mouse Nkx3.1 antibody is the IgG fraction from rabbit anti-sera generated by immunizing the animals with purified recombinant mouse Nkx3.1 protein. To improve the specificity of the antibody only the N-terminal domain of mouse Nkx3.1 was produced as immunogen. The IgG fraction was prepared by protein A affinity chromatography. IgG specific to mouse Nkx3.1 was further purified using an affinity matrix produced by cross-linking the immnunogen to agarose.