We identified significant associations between ten immune phenotypes and malignant thymic tumors (P < 0.001 for IVW), of which, seven were harmful to malignant neoplasm of thymus: Memory B cell %B cell (B cell panel), CD20− AC (B cell panel), CD3 on CD28+ CD45RA− CD8br (T cell panel), CD28 on CD28+ CD4+ (T cell panel), CCR2 on CD14+ CD16+ monocyte (monocyte panel), CD80 on plasmacytoid DC (DC panel), and CD80 on CD62L + plasmacytoid DC (DC panel); and three were protective to malignant neoplasm of thymus:. Here, SELL is linked to cancer.