DDR2 and breast neoplasm: As anticipated, in all breast tumor cell lines (human BT549, Hs578 T and MDA-MB-231 cells, as well as mouse 4T1 cells) depletion of DDR2 inhibited Matrigel invasion (Fig. 2A; Fig. S2A–D) and, for BT549 and 4T1 cells, migration through 3D collagen I matrices (Fig. 2D; Fig. S2E).