Th epigenetic landscape metaphor is extended to multiple scales of biology, stacking them up, including molecular, cellular and tissular scales (Fig. 5-6); they may be referred to as "episystemic landscapes". At the tissular level the same concept can represent not cell differentiation trajectories but developmental routes and organogenesis. A location on such "epi-tissular landscape" represents a particular tissue, typically composed of multiple cell types, connecting the tissular layer to the cellular layer and so on (Fig. ).