In breast tumor cells, DDR2 regulates tumor cell collective invasion by sustaining a SNAIL1 (SNAI1)-mediated epithelial–mesenchymal transition (EMT) invasive program, particularly in keratin 14 (KRT14)-positive leader cells (Zhang et al., 2013; Hwang et al., 2019), as well as full activation of collagen-binding integrins (Bayer et al., 2019). This evidence concerns the gene SNAI1 and breast neoplasm.