CCL21 and central nervous system cancer: ATRA partially reversed glioma sphere growth in stem-like cancer cells and promoted differentiation in U87MG-SLC cells.NSPc1 knockdown resulted in impaired neurospheres’ formation, self-renewal abilities, and the downregulation of stemness markers CD133 and Sox2 NSPc1 epigenetically repressed the expression of RDH16 by directly binding to the RDH16 promoter