Adenocarcinomas showed higher expression of SLC1A5 and GLS2 in both protein (P = 0.08 and P = 0.019, respectively) and mRNA level (P < 0.001 and P = 0.003, respectively) (Fig 2, Table 1), compared to squamous cell carcinomas. This evidence concerns the gene SLC1A5 and adenocarcinoma.