PMP22 and plexiform neurofibroma: We used neurofibroma sphere culture, a system enabling detection of growth and self-renewal of nervous system stem cells/progenitors, to determine whether Pmp22 was related to SCP growth upon loss of Nf1. We knocked down Pmp22 from Runx1fl/fl;Runx3fl/fl;Nf1fl/fl;DhhCre mouse DRG/neurofibroma-derived spheres, which has high Pmp22 expression using shPmp22s or shNT.