Cells invade preferentially from the ends of bifurcating ducts.

(A) In control tissues cells invade preferentially from the ends of bifurcating ducts. Decreasing contractility partially inhibits invasion, while increasing contractility causes delocalization of invasion. (B) Quantification of tissues with invasion at the end and the duct region of each tissue at 3000 MCS. Simulations were run with high proliferation (mitosis every 65 MCS) and high apoptosis (1% probability), 20 times for each of the parameters described in Fig. 6F–G.