National Center for Biotechnology Information (NCBI)This is the homepage for NCBI. NCBI is a division of the National Library of Medicine. It provides access to biomedical and genomic information through numerous databases. Check out the Resource List and Popular Sources to find data related to gene and genome sequences, information on chemical structures, identifiers, chemical and physical properties, biological activities, patents, health, safety, toxicity data via PubChem, and taxonomy information for over 160,000 organisms.