In addition, both the insulin receptor isoform A and isoform B are able to form hybrids with the IGF-I receptor in various rodent and human cell lines or hepatoblastoma cells: the hybrid receptor with the insulin receptor isoform A has an higher affinity for IGF-I and also binds IGF-II and insulin, whereas the hybrid receptor with the insulin receptor isoform B has a high affinity only for IGF-I. The gene discussed is IGF1R; the disease is hepatoblastoma.