HHLA2 and cancer: In addition, to further explore the relation of LncTUG1 expression with immunity in cancer, we assessed the correlation of TUG1 expression with that of some immune checkpoint molecules (CD200, CD274, CD40, CD70, CD80, HHLA2, LGALS9, TIGIT, TNFSF4, and VTCN1) in various cancers (Fig. 1C).