MDCK cells cultured in collagen I showed later cell polarization during cyst formation and formed lumen by center cell apoptosis passing through a multi lumen state, whereas MDCK cysts grown in laminin rich Matrigel induced early cell polarization and formed lumen through cell proliferation with almost negligible center cell apoptosis (Martin-Belmonte et al., 2008). The gene discussed is LAMB2; the disease is cyst.