Loss of heterozygosity at microsatellite marker D6S273 within the HLA class III region was earlier observed at a high frequency in DNA samples from cervical intraepithelial neoplasias and cervical cancers. Three genes were identified in the region according to published data. The mRNA sequences available from GenBank were examined in silico, the exon-intron structure of the genes was analyzed, and the LY6G6D expression was studied in tumor cell lines. LY6G6D proved to consist of nine exons and to include, earlier identified, G6D and G6F. D6S273 was localized to the last intron 8 of LY6G6D. The third gene, LY6G6E, consists of four exons and is in intron 6 of LY6G6D in the opposite orientation. LY6G6D was assumed to have three main mRNA transcripts, which are encoded by the same open reading frame but differ in exon composition: MEGT1 consists of exons 1-4, 8, and 9; G6F consists of exons 1-6; and G6D consists of exons 7-9 of LY6G6D. A high homology to the immunoglobulin superfamily was observed within region 20-120 of the MEGT1 and G6F proteins by in silico translation of their mRNAs.