To determine the roles of N-linked glycosylation in regulating PD-L1 pro-metastatic activities in breast cancer cells, we used kifunensine (K) and swainsonine (S), which are inhibitors of key enzymes participating in N-linked glycosylation: α-mannosidase I and α-mannosidase II, respectively [29,30]. Here, CD274 is linked to breast cancer.