Conceptual steps common to all the proposed simulations. a), Schematization of the modelling of the external shape. V = Volume, SI = Sphericity Index, r_x, r_y and r_z: semiaxes of the simulated ellipsoid. b), creation of the irregular external shape. c) Simulation of the cytoplasm. r_x,cyto, r_y,cyto and r_z,cyto: semiaxes of the ellipsoid simulating the cytoplasm. d), Simulation of the nucleus. r_x,nuc, r_y,nuc and r_z,nuc: semiaxes of the ellipsoid simulating the nucelus, NCR = Nucleus to Cell Ratio.