Provides polymerase chain reaction (PCR) and qPCR primers. PrimerBank contains 497 156 primers that cover 36 928 human and mouse genes, corresponding to around 94% of all known protein-coding gene sequences. These primers have been selected from millions of primer candidates using an improved algorithm and current genomic information. Users can access all stored information (primer sequences and annotations, primer validation data, as well as gene annotations) from the search interface. High-throughput qPCR using PrimerBank primers has several advantages: (i) the primers work under the same conditions and thousands have been experimentally validated and (ii) the expression profiles of thousands of genes can be determined at the same time.