The result of positive expression and the size of the area showing ARL4C expression were not correlated with the T grade (tumor size and depth of invasion) or N grade (degree of lymph node metastasis) of the tumor (Table 1), suggesting that ARL4C might be involved in the initiation, rather than progression, of lung SCCs. This evidence concerns the gene ARL4C and metastatic malignant neoplasm in the lymph nodes.