The present invention provides novel regulatory elements and vectors for the expression of one or more proteins in a host cell. The present invention also provides methods for expressing one or more proteins, such as antibodies, in a host cell. These methods utilize the novel regulatory elements and vectors of the present invention for the expression of proteins in a host cell. The host cells are used for producing various protein products, including but not limited to pharmaceutical proteins, antibodies, variants of proteins for use in screening assays, and for direct use in high throughput screening.