EZH1 encodes a protein of 747aa that displays 55%aa identity overall with the Drosophila homolog.1 The strong sequence conservation suggested potential roles for EZH1 in human development as a transcriptional regulator and as a component of protein complexes that preserve heterochromatin stability. EZH1 is expressed as 2 major transcripts in all adult and fetal human tissues evaluated.. Analysis of an EZH1 cDNA revealed an unusual splicing event involving EZH1 and a tandemly linked gene GPR2 and suggested a potential mechanism for modifying the EZH1 protein in the conserved C-terminal domain. The GPR2 gene maps to 17q21.1-q21.3 in the vicinity of the BRCA1 gene.