Allelic losses of the q13.3 region of chromosome 19 have been documented in malignant gliomas, neuroblastomas, and ovarian carcinomas, strongly suggesting the presence of a 19q13.3 tumor suppressor gene. Deletion mapping in tumors over the past decade has narrowed the candidate region considerably but has produced partially conflicting results, with some small candidate regions defined only by isolated tumors with deletions. Mutation and expression screening of genes from the most likely candidate regions has failed to identify the gene of interest, perhaps because of the conflicting deletion mapping data. The recently increased public availability of human genomic sequence, combined with improved bioinformatics capabilities, has now made it possible to map much larger candidate regions in considerable detail. We have manually generated a transcript map that spans most of the 19q13.3 tumor suppressor candidate region, from D19S219 to D19S246, with a resolution and quality superior to that of computer-generated maps. These results are presented in the hope that an improved map of the candidate region will facilitate further widespread screening and eventual identification of the gene or genes deleted in human gliomas, neuroblastomas, and ovarian cancers.