The DNA Sequencing Core Lab provides a variety of services to the NIEHS scientific community. The Sequencing Core assist labs in SNP discovery, mutagenesis detection, custom primer design, expression construct design, and optimization of PCR. Our main focus has been to provide DNA sequence data to individual investigators in a timely manner. The DNA Sequencing Core works with individual labs to make DNA expression constructs. The Sequencing Core has also collaborates with investigators at NCI to further understand the SPANX gene family. Genetic linkage studies indicate that germ line variations in a gene or genes on chromosome Xq27-28 are implicated in prostate carcinogenesis. The linkage peak of prostate cancer overlies a region of approximately 750 kb containing five SPANX genes (SPANX-A1, -A2, -B, -C, and -D) encoding sperm proteins associated with the nucleus; their expression was also detected in a variety of cancers. We continue to further characterize this region of the genome. We speculate that the predisposition to prostate cancer in X-linked families is an example of a genomic disease caused by a specific architecture of the SPANX gene cluster. Currently we are investigating the possibility of two new gens located in this region of the X chromosome. One a new SPANX family member and the other a micro RNA encoding gene.