VISTA is expressed on naïve T cells, NK cells, Tregs, monocytes, macrophages, DC and neutrophils; VISTA and its ligands are also overexpressed on cancer cells (in particular on cancer stem cells), tumor-infiltrated myeloid cells and Tregs in TME; VISTA can interact with itself and with its ligands in trans as well as in cis. Here, VSIR is linked to neoplasm.