. A) Diagram resulting from a vertex model simulation that includes cell proliferation. B) Diagram resulting from a vertex model simulation that includes cell proliferation and heterogeneous reduction of line tension among the tissuecells. C) Diagram resulting from a vertex model simulation with heterogeneous reduction of line tension and an impairment of the cell division when tension value is under the 30 percent of the initial value D) Similar simulation than in (C) with a threshold of 40 percent. 