PPAT and carcinoma: Both glucose and nitrogen metabolism are altered during the malignant progression of carcinoma (Kodama et al. 2020; Zhang et al. 2017), and elevated levels of c-Myc induce the expression of enzymes, such as phosphoribosyl pyrophosphate aminotransferase (PPAT), which is involved in nucleotide biosynthetic pathways (Cunningham et al. 2014; Liu et al. 2008).