Among the variables that differentiated SCLCs from LCNECs, high Snail1 (p = 0.0001), high Snail2 (p = 0.0001) and high Twist (p = 0.001), as well as reduced E-cadherin (p = 0.001), β-catenin cytoplasmic expression (p = 0.0001) and cytoplasmic pattern of N-cadherin (p = 0.001), were more frequent in SCLC vs. LCNEC. This evidence concerns the gene TWIST1 and small cell lung carcinoma.