MycoRegDB is currently the only available database of promoter/regulatory elements across various mycobacterial species. The first release of MycoRegDB (Supplementary Figure S1) contains 290 annotated DNA motifs (174 promoters and 116 transcription factor binding sites) described in 81 research papers. For each database entry, MycoRegDB gives a variety of information such as gene annotation, CDS positions, promoter/regulatory sequence (with TSP/binding site explicitly marked), TSP-CDS/Motif-CDS distance and hyperlinks to relevant reference(s). Wherever applicable, it also provides hyperlinks to gene information from TubercuList, BCGList and Leproma (http://genolist.pasteur.fr/). These resources are helpful for (i) retrieving DNA/protein sequences, (ii) knowing family classification of genes, and (iii) providing cross-references to UniProt, PDB, PFAM and COG databases. The MycoRegDB will be kept up-to-date in future releases.