GLS and adenocarcinoma: This is in contrast to the findings of others, who demonstrated that SLC1A5 expression is associated with squamous cell histology.10, 25, 26 In an in vivo mice study, the glutamine tracer 5‐11C‐(2S)‐glutamine (11C‐Gln) uptake was higher in a squamous cell carcinoma than an adenocarcinoma, although n = 1 for both histologies, so the question is whether these tumors are a reliable representation of these histologies.27 However, we also examined GLS2 protein expression and mRNA expression of SLC1A5, GLS and GLS2.