GAMT and neoplasm: We analyzed the expression of key enzymes involved in the arginine catabolism pathway, and found that guanidinoacetate methyltransferase (GAMT), agmatinase (AGMAT), ARG2, and ornithine aminotransferase (OAT) levels, as well as arginine metabolism pathway scores of Tfh tumor cells, were notably higher in the RR group than in the ND group (Figure 3F,G, and Figure S3G–I, Supporting Information).