Abstract: The method of the invention provides for producing a heterologous protein in mammalian host cells having nucleic acid encoding Hepatitis B X protein and the heterologous protein, by growing mammalian host cells selected from the group consistng of HKB11, CHO, BHK21, C2C12, and HEK293 cells, by growing mammalian host cells in non-adherent suspension culture, or by growing mammalian host cells which contain nucleic acid providing exogenous X-box Binding Protein, XBP1s. The conditions should be such that HBx, exogenous XBP1s if present, and the heterologous protein are expressed by the mammalian cells. The invention includes compositions for carrying out the method.

Abstract: The method of the invention provides for producing a heterologous protein in mammalian host cells having nucleic acid encoding Hepatitis B X protein and the heterologous protein, by growing mammalian host cells selected from the group consisting of HKB11, CHO, BHK21, C2C12, and HEK293 cells, by growing mammalian host cells in non-adherent suspension culture, or by growing mammalian host cells which contain nucleic acid providing exogenous X-box Binding Protein, XBP1s. The conditions should be such that HBx, exogenous XBP1s if present, and the heterologous protein are expressed by the mammalian cells. The invention includes compositions for carrying out the method.

Abstract: The method of the invention provides for producing a heterologous protein in mammalian host cells having nucleic acid encoding Hepatitis B X protein and the heterologous protein, by growing mammalian host cells selected from the group consisting of HKB11, CHO, BHK21, C2C12, and HEK293 cells, by growing mammalian host cells in non-adherent suspension culture, or by growing mammalian host cells which contain nucleic acid providing exogenous X-box Binding Protein, XBP1s. The conditions should be such that HBx, exogenous XBP1s if present, and the heterologous protein are expressed by the mammalian cells. The invention includes compositions for carrying out the method.

Abstract: The present invention provides an improved, expression system for the regulated expression of an encoded protein or nucleic acid therapeutic molecule in the cells of a subject, for use in the treatment of disease. In particular, the present invention provides an improved, regulated gene expression system, and pharmaceutical compositions and uses thereof for treatment of disease.

Abstract: The invention provides for synthetic ligands that bind to class I receptor tyrosine kinases. The ligands are analogous in structure to naturally occurring ligands. The modified ligands however, have eliminated the mid-sequence (B) domain present in the native ligands and replaced it with a peptide bridge which links the amino (A) and carboxy (C) domains.