PLXNA1 and carcinoma: Therefore, we determined whether Sema3A alters the motility response of MDA-MB-231 breast carcinoma cells on increasing coating concentrations of type I collagen, fibronectin, and laminin I. MDA-MB-231 carcinoma cells express the Sema3A coreceptors, plexin A1 and neuropilin-1, making it a suitable cell line for this study [16].