Artificial TERT promoters, which are useful for enhancing the differential expression of operably linked heterologous nucleic acid sequences, such as polypeptide cytotoxins, are disclosed herein. Methods for treating disease cells, such as cancer cells, while minimizing effects on normal, somatic cells by administering therapeutically effective amounts of heterologous nucleic acid sequences operably linked to artificial TERT promoters are provided. Kits containing artificial TERT promoters for enhancing differential expression are also provided.