PTBP1 is highly expressed in undifferentiated neural stem cells, while PTBP2 is a marker of differentiated neurons.222 PTBP1, which is highly expressed in undifferentiated neural stem cells, regulates PTBP2 pre-mRNA exon 10 AS, leading to NMD, thereby resulting in the reduction of PTBP2 expression, inhibition of the differentiation and maturation of neural stem cells and NPCs and promoting tumor occurrence.96 On the other hand, PTBP2 is a marker of differentiated neurons. The gene discussed is PTBP1; the disease is neoplasm.