Pioneer factors reprogram specialized cell types (germ cells, fibroblasts) to pluripotency (iPSC, early embryonic cells). Expression of other pioneer factors can transdifferentiate fibroblasts to additional cell types, such as neurons and can also drive differentiation from naïve (ESC) to more specialized cell types (endoderm, EpiLC). A subset of pioneer factors involved in each conversion are listed along the arrows, which indicate the direction of the conversion events. The color of the cell represents the relative degree of differentiation with dark orange being the most differentiated.