The PD-DOC is committed to facilitating PD research, therefore the PD-DOC website provides electronic links to Outside PD Databases that are not managed by the PD-DOC but which may be of use to PD researchers. An example of such a database is the National Center for Biotechnology Information (NCBI) website posts the database of Genotype and Phenotype (dbGaP) which was developed to archive and distribute the results of studies that have investigated the interaction of genotype and phenotype.