ERBB4 and medulloblastoma: Flow cytometry analysis revealed that MET (mean±sd: 74.9% ± 13.9%), EGFR (mean±sd: 77.4% ± 10.9%) and ErbB2 (mean±sd: 67.8% ± 10.3%) are highly expressed in all medulloblastoma cell lines, whereas ErbB3 (mean±sd: 4.0% ± 3.6%) and ErbB4 (mean±sd: 1.5% ± 2.1%) are barely expressed at all (Fig 1 and S1 Fig).