MYCN and neuroblastoma: Supplementary Table S1 displays the clinical features of the neuroblastoma tumors used in this study. SYK was present at varying levels in 40 out of 42 neuroblastomas and 3 out of 3 ganglioneuromas (Table 1). Figure 1B,C display a representative staining of SYK in non-MYCN-amplified and MYCN-amplified tumors, respectively. In both, the cytoplasm and the nucleus, a positive SYK staining was observed. SYK-positive tumor cells were present in 31 out of 32 non-MYCN-amplified neuroblastomas and in 9 out of 10 MYCN-amplified tumors (Table 1).