Before revision: Progress in cell reprogramming recently has revived Waddington's concept of an epigenetic landscapein the term of a quasi-potential function and cell attractors in a complex dynamical system embodied by the cell's gene regulatory network (GRN) . The quasi-potential of network states have biological significance because the relative stability  in a multi-stable dynamical system offers a measure of the effort for the transition between attractors .
After revision: Progress in cell reprogramming recently has revived Waddington's concept of an epigenetic landscapein the term of a quasi-potential theory to represent the Waddington's landscape. The Quasi-potential U(x), derived from interactions in the gene regulatory network (GRN) . The quasi-potential of network states have biological significance because the relative stability in a multi-stable dynamical system offers a measure of the effort for the transition between attractors .