| abstract |
Epithelial cells expressing foreign genetic material are described. The foreign genetic material can be DNA or RNA which does not occur in. epithelial cells; DNA or RNA which occurs in epithelial cells; but is not expressed in them at levels which are biologically significant; DNA or RNA which occurs in epithelial and has been modified so that it is expressed in epithelial cells; and any DNA or RNA which can be modified to be expressed in epithelial, cells, alone or in any combination thereof. In addition, epithelial cells of the present invention can express genetic material encoding a selectable marker by which cells expressing the foreign genetic material can be expressed. |