MUC1 and familial pancreatic carcinoma: They found that decitabine application (a hypomethylating agent that can increase tumor antigen expression by demethylating DNA) could upregulate mucin 1 (MUC1) expression in resistant CAPAN1 pancreatic cancer cells, with lower antigen expression induced by previous MUC1 CAR-T treatment, making them vulnerable to CAR-T therapy [12].