FN1 and cancer: Invasive cancer cells moving within fibrillar collagen and fibronectin 3D cell-derived matrix (CDM; Cukierman et al., 2001) followed the topology of fibrils with defined lamellipodial and filopodial protrusions at the cell front (Caswell and Zech, 2018, Paul et al., 2015) (Figures 1A and S1A), similar to that on 2D substrates.