Nevertheless, two key enzymes responsible for the maintenance of tumour glycolysis in aerobic conditions - lactate dehydrogenase A (LDHA) [23] and pyruvate kinase type M2 (PKM2) [24] - were among those identified in our analysis as up-regulated by STAT1 at both the gene and protein level (see Table 2 and Figure 4). This evidence concerns the gene PKM and neoplasm.