In addition to validating Nrg1/Nrg1 and Tgfa/Tgfα mRNA and protein as anticorrelated biomarkers of schwannoma heterogeneity, we found a spatial bias of Nrg1−expressing cells within lesions in proximity to DRG soma, a source of Nrg1 that could drive the feedforward Nrg1 expression that we see in vitro. Here, NRG1 is linked to schwannoma.