PD-1 and PD-L1 may be markers predicting the risk of infectious complications in AP patients (Pan et al., 2017; Yu et al., 2021; Chen et al., 2017), and elevated CTLA-4 and PD-1 expression levels may prevent early pancreatitis (Chuanlin Wu and Bai, 2021). Here, CTLA4 is linked to pancreatitis.