The present invention utilizes a relay station operable to receive, from a base station, a first signal to control transmitting operation of a mobile station and operable to receive a second signal transmitted from said mobile station in accordance with the first signal. The feedback network includes a first resistance that communicates with an input and an output of the amplifier. The target cell is contacted with population of adeno-associated viral vectors under conditions sufficient to produce a hetero-concatemer in the cell, where the hetero-concatemer includes a functional expression cassette having an intron that includes an ITR sequence.