Esselens and co-workers had shown that MMP-processed Sema3C promotes tumour cell migration (Esselens et al, 2010); furthermore, Lee and Yutzey (2011) showed that Sema3C expression is induced by Twist1, an epithelial to mesenchymal transition (EMT)-inducing transcription factor implicated in cancer progression. The gene discussed is SEMA3C; the disease is cancer.