TH and neuroblastoma: In 2009, the International Neuroblastoma Risk Grading Group (INRG) established a standard clinical method to detect microscopic lesions in children with NB, including immunocytochemical staining for GD2 antigen on the cell surface and real-time fluorescence quantitative PCR for tyrosine hydroxylase, a critical enzyme in GD2 synthesis [11,18,19,32].