I use BiomaRt to build a table of the coordinates of all the exons in a gene transcript: colnames = c ("ensembl_exon_id", "rank", "exon_chrom_start", "exon_chrom_end", "strand") queryFields = 'entrezgene' queryValues = geneID tbl.exons = getBM (colnames, queryFields, queryValues, mart=human.mart) Since not all bases in an exon (even interior exons) are in fact coding, I now discover that I actually want the coordinates of the coding regions within each of the exons, not just the exon boundaries. Sometimes, maybe often (except for 3' and 5' UTRs) these coordinates are the same. Can anyone tell me how to query BiomaRt for the per-exon coding boundary coordinates? Thanks! - Paul