Guanosine triphosphate-13C (GTP-13C) dilithium is 13C-labeled Guanosine triphosphate (HY-113225). Guanosine triphosphate (GTP) is a critical nucleotide and regulator of cellular metabolism. Guanosine triphosphate promotes ribosomal DNA localization, pre-rRNA transcription and ribosome biogenesis by binding to RNA polymerase I and GPN proteins (GPN1/3). Guanosine triphosphate links MYC-dependent ribosome biogenesis to nucleotide sufficiency, acts as a metabolic gatekeeper supporting protein synthesis, DNA/RNA synthesis and cellular signal transduction, while also participating in the physiological activities of pancreatic beta-cells and serving as an oxidative substrate for reactive oxygen species. In small cell lung cancer with high MYC expression, Guanosine triphosphate accumulates through the IMPDH-driven synthetic pathway, thereby affecting apoptosis and mitotic processes. Guanosine triphosphate is used in the research of small cell lung cancer, hepatoblastoma and cellular metabolism[1][2][3].