An isolated mRNA sequence for expression of one or more polypeptides within one or more target organs, the sequence comprising at least one coding sequence which codes for the at least one polypeptide, at least a first untranslated region (UTR) sequence and a plurality of micro-RNA (miRNA) binding site sequences. Each oft he miRNA binding site sequences is located within, immediately 5' to or immediately 3' to, the first UTR sequence； and the miRNA binding site sequences allow for differential expression of the coding sequence in at least a first and a second cell type within the target organ or organs. Methods for using the composition are provided, particularly in treatment of disease, such as cancer of the liver, brain, lung, breast,pancreas, colon and kidney.
