PDCD1LG2 and pancreatic neoplasm: Recent studies have discovered that the human breast cancer susceptibility gene 2 (BCRA2), which is strongly linked to both high PD-L2 in TCs and poor survival in patients wih PDAC, inherits mutations in 1–4% of pancreatic cancer patients, indicating the possible impact of BCRA2 on PD-L2 expression [43].