RSPO1 and neoplasm: In this study, single-nucleus RNA sequencing (snRNA-seq) and single-cell Assay for Transposase-Accessible Chromatin using sequencing (scATAC-seq) showed that NOTCH-driven CP tumors partitioned into clusters identified as epithelial-like, mesenchymal, endothelial, immune, neuronal, and glia-like cells, similar to populations in normal CP in mice.3 Though tumor cells reside in an epithelial-like compartment, they arise from binary glial progenitors and exhibit an enrichment of genes associated with glial progenitors in the rhombic lip, including Sox2, Zfp423, and Rspo1.