PTBP1 and esophageal squamous cell carcinoma: NAT10 induces ac4C modification of several targets such as the lncRNA CTC-490G23.2 that interacts with polypyrimidine tract-binding protein 1 (PTBP1) to increase CD44 alternative splicing in primary ESCC: the lncRNA acts as a scaffold to increase the binding of CD44 pre-mRNA to PTBP1, resulting in an oncogenic splicing switch from the standard isoform CD44s to the variant isoform CD44v(8-10) [117].