such dramatic cell lineage changes can also be induced between distantly related somatic cell types. In 2010, we have shown that fibroblasts can be reprogrammed into induced neuronal (iN) cells illustrating that direct lineage conversion is possible even between cell types representing different germ layers [6]. Following our work more examples were added such as the induction of cardiomyocytes, blood cells and hepatocytes from fibroblasts [7–10]. In this review, we will focus on several aspects of iN cell reprogramming and discuss methods of improving reprogramming efficiency and criteria to functionally characterize those iN cells.
