The mean Sox2 and Lin28 expression levels in the 28 cases with a large tumor size (>5 cm) were 3.79±0.29 and 4.66±0.40, respectively; whereas in the 29 cases with a small tumor size, the levels were 2.79±0.29 and 3.55±0.31 (P=0.02 and 0.03), respectively. This evidence concerns the gene SOX2 and neoplasm.