Recent advances in therapeutically important cell fate reprogramming fuelled a renaissance in the use of mRNAbased
gene vectors. Thus, mRNA vectors were successfully employed to induce lasting epigenetic changes in
various target cells making them short-listed vector candidates for the manufacture of therapeutic engraftment
materials for autologous transplantation, artificial human tissues for drug discovery via high-throughput screening
projects and also for therapeutic cell trans-differentiation directly in the human body. De-differentiation of cells into
‘induced pluripotent stem cells’, transgene-directed differentiation and trans-differentiation require the simultaneous
delivery of a number of regulatory factors, and, favourably, potent reprogramming vector cocktails can be
straightforwardly assembled from a selection of mRNA species. In addition, several proteins can be conveniently
expressed from a single mRNA using internal ribosome entry sites (IRESes) or, alternatively, fusion proteins
supplemented with ‘polypeptide-cleaving’ ribosome skipping sequences. This review is focused on the design and
production of cell-fate changing mRNAs.