These receptors interact with ligands [such as PD-L1, cytotoxic T-lymphocyte associated protein 4 (CTLA-4), LAG-3, T cell immunoreceptor with immunoglobulin and immunoreceptor tyrosine-based inhibition motifs (ITIM) domain (TIGIT)] on tumor cells or other immune-regulating cells, leading to inhibition of self-immunity and potentially enabling tumor immune escape. This evidence concerns the gene CTLA4 and neoplasm.