LGALS9 and primary cutaneous T-cell non-Hodgkin lymphoma: It was, for example, recently reported that the malignant T cells secrete galectin-9 and that increased expression of galectin-9 in CTCL skin lesions is associated with a reduced infiltration of CD8 T cells while high serum levels are correlated with disease severity markers (Nakajima et al., 2019).