Dear All, I was wandering if giving the human name of the chromosome and the start and end position of the chromosome for the human, i.e. filters = c("chromosome_name", "start","end"), I can retrieve the coordinates of the corresponding region in mouse. It seems that through the getLDS command (biomaRt user guide, 4.11 Task 11) the attributes have "start_position","end_position", which specify start end end of genes in the region, but these do not encompass the whole region Thank you! ---------------------------------------------- Sergii Ivakhno PhD student Computational Biology Group Cancer Research UK Cambridge Research Institute Li Ka Shing Centre Robinson Way Cambridge CB2 0RE England +44 (0)1223 404293 (O) +44 (0)1223 404128 (F) http://www.compbio.group.cam.ac.uk <http: www.compbio.group.cam.ac.uk=""/> / [[alternative HTML version deleted]]