PDCD1 and familial pancreatic carcinoma: Similar to pancreatic cancer, Yuan et al. (Yuan et al. 2021) reported that hyper-O-GlcNAcylation could improve the self-renewal capacity of esophageal cancer stem cells (ECSCs) and promote the high expression of programmed cell death 1 (PD1) in CD8 + T cells, resulting in immune escape.