POU5F1 and cancer: Furthermore, none of the spheroid cultures expressed stemness related genes like SHH, OCT4, KLF4, or LIN28A, that were enriched in WT cancer stem cells in the analysis by Shukrun et al. Only stromal and in part epithelial spheroids showed moderate expression of the stemness-related genes LGR5, LIN28B, and POU3F3. The absence of these genes in blastemal spheroids suggests alternative pathways that ensure self-renewing capacity and proliferation in vitro, while stromal spheres may be more dependent on classical stemness genes.