CTLA4 and metastatic malignant neoplasm in the lymph nodes: ICI marker analysis indicated that the lymph node metastasis group exhibited non‐significant differences in immune checkpoint gene expression levels, except for PD1, TIGIT, and CTLA4, which were significantly higher than those in the non‐metastasis group (p = 0.0008, p = 0.0004, p = 0.0093) (Table S3).