Immunohistochemical (IHC) evaluation studies of tissue sections [34] or TMA (tissue microarray) [10] from HNSCC patients—including specimens ranging from normal to metastatic stage and originating from the tongue, oral cavity, lip, larynx, and lymph-nodes—(Figure 2) displayed an upregulation of GLS enzyme expression in tumor tissues compared to normal mucosa (Table 2). This evidence concerns the gene GLS and neoplasm.