SNAI1 and squamous cell carcinoma: E-cadherin has a central role in maintenance of the epithelial cell-type characteristic and the SNAIL/SIP1 inhibition of E-cadherin expression in squamous carcinoma cells accelerates dedifferentiation and invasion (Battle et al, 2000; Cano et al, 2000; Carver et al, 2001; Comijn et al, 2001).