Guanosine triphosphate-15N5 (GTP-15N5) dilithium is 15N labeled Guanosine triphosphate (HY-113225). Guanosine triphosphate dilithium (GTP) is a critical nucleotide and regulator of cellular metabolism. Guanosine triphosphate dilithium promotes ribosomal DNA localization, pre-rRNA transcription and ribosome biogenesis by binding to RNA polymerase I and GPN proteins (GPN1/3). Guanosine triphosphate dilithium 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 dilithium accumulates through the IMPDH-driven synthetic pathway, thereby affecting apoptosis and mitotic processes. Guanosine triphosphate dilithium is used in the research of small cell lung cancer, hepatoblastoma and cellular metabolism[1][2][3].