SOX2 and carcinoma: Eleven SOX2 positive samples (7 belonging to expression score 3 and 4 of score 2), 4 SOX2 negative samples as well as 3 lymph-node samples showing high SOX2 expression (score 3) were analyzed by FISH to explore whether aberrant SOX2 expression is a result of gene amplification as previously reported in other carcinomas [20].