ICOS and cancer: Our results found a correlation between the level of SERCA3 and immune-activating and immunosuppressive genes, including PDCD1 (PD-1), CTLA-4, TIGIT, and ICOS. By analyzing the correlation between SERCA3 expression and immune checkpoints we found that SERCA3 expression was related to immune checkpoints, including CTLA-4, PDCD1, and ICOS in most types of cancer.