Table 1.

Prediction of the possible O-linked glycosylated sites on PD-1 protein using NetOGlyc 4.0 Server.

Amino acid position	Domain	Predicted score
T145	Stalk	0.767
T153	Stalk	0.967
S157	Stalk	0.865
S159	Stalk	0.898
S273	Cytoplasmic domain	0.671

All positions with a score greater than 0.5 are listed in the table.