PHOX2B and neoplasm of thorax: Two mice in the combination therapy group ultimately died from thoracic tumors, of which 1 was a PHOX2B+ thoracic neuroblastoma (suggesting a metastatic or primary thoracic neuroblastoma) and the other a PHOX2B–MYCN–CD45+CD3+ lymphoma (Supplemental Figure 6, B and C).