Furthermore, Spearman correlation between each SUMOylation regulatory gene and immune cell revealed that CAPN3 was widely associated with various immune cells such as CD8+T cells (r = 0.32), DCs (r = 0.343), iDCs (r = 0.432), Mast cells (r = 0.468), Tcm (r = 0.421), Tem (r = 0.275), TFH (r = 0.291), Th2 cells (r = 0.563), and Treg (r = 0.115), indicating that CAPN3 among SUMOylation regulatory genes is closely associated with immune cell infiltration in the tumor microenvironment of lung adenocarcinoma. The gene discussed is CAPN3; the disease is lung adenocarcinoma.