Histological evaluations of the tumor mass collected after 60 days of in vitro growth confirmed that the REC-3D tumoroids displayed features of poorly differentiated/differentiating neuroblasts (Figure 1e) with positive immunoreactivity for CD56, tyrosine hydroxylase (TH), and particularly for the CD133 stem cell marker (Figure 1f). This evidence concerns the gene PROM1 and neoplasm.