The invention provides fusion proteins comprising an exendin-4 fused to a transferrin via a polypeptide linker, as well as corresponding nucleic acid molecules, vectors, host cells, and pharmaceutical compositions. The cargo platform system may comprise a sub-frame having deck-rails for attachment to a vehicle frame, a platform having deck-rails for removably coupling to the sub-frame, and a jack system comprising a first jack, a second jack, a third jack, and a fourth jack removably attached to a left front corner, a right front corner, a left rear corner, and a right rear corner respectively. The signal modifying circuitry is arranged and configured to receive a PLL status signal indicative of the lock state of the PLL circuitry, and to modify the at least one property of the output signal in response to the PLL status signal indicating that the PLL circuitry is in a locked state.