CXCL9 and neuroblastoma: As we had also profiled IFN-γ responses of two MYCN-non-amplified NB cell lines SK-N-FI and SK-N-AS (high vs low H3K27me3 signals at CXCL9, CXCL10 and CXCL11 loci) overlapping with the ChIP-seq study,28 we consistently noticed that low H3K27me3 signals in SK-N-AS cells correlated with strong CXCL9, CXCL10 and CXCL11 gene induction by IFN-γ treatment alone (online supplemental figure 3G, H, J).