“…The cell species velocity is obtained from a Darcy's law coarse scale reformulation of the inertialess momentum equation, which is the instantaneous equilibrium among the following forces: pressure, resistance to motion (cell-adhesion), elastic forces, forces exchanged with the ECM leading to haptotaxis and chemotaxis and other mechanical effects (e.g. [59,212,55,74,181,127,11,10,12,51,3,25,48,79,16,133,90,39,40,5,135,6,43,50]. Cells produce proteases, which degrade the matrix locally, making room for cells to migrate.…”