Apart from PD-1/PD-L1 monoclonal antibodies, other immune checkpoint inhibitors (ICIs), such as cytotoxic T lymphocyte antigen 4 (CTLA-4), T cell immunoreceptor with immunoglobulin and ITIM domains (TIGIT), immune checkpoint T cell immunoglobulin and mucin domain 3 (TIM-3), and lymphocyte activation gene 3 (LAG-3), are reported to be upregulated in tumor-infiltrating lymphocytes. The gene discussed is CTLA4; the disease is neoplasm.