Aristaless-related genes are a group of paired-related homeobox genes which play a role in regulating vertebrate embryogenesis. The homeodomain transciption factor aristaless-like 3 (ALX3) is expressed in mouse embryos from 8 days of gestation, predominantly in neural crest-derived mesenchyme and in lateral plate mesoderm. Expression analysis of human and mouse tissue reveals predominant ALX3 expression in brain tissue. The Alx3 gene maps to chromosome 1p23-p13 and encodes a 343 amino acid protein. Preferential methylation of Alx3 occurs in advanced-stage neuroblastoma and may repress ALX3 expression. Treatment with the methylation inhibitor 5-aza-2