S100B and neoplasm: The GNP signature was defined by abnormal neural development features such as co-expression of stem cell transcription factor SOX2 and astrocyte lineage marker S100B (Ikushima et al., 2009; Raponi et al., 2007) and simultaneous high basal phosphorylation of multiple signaling effectors downstream of receptor tyrosine kinases reported to be important in tumor biology (Bhat et al., 2013; Carro et al., 2010; Dolma et al., 2016; Fan et al., 2017; Tan et al., 2019; Wei et al., 2013; Figure 1—figure supplement 4).