FIGURE 4.

Relationship between human leukocyte antigen (HLA) class I expression and 5‐year overall survival (OS) of patients with oral squamous cell carcinoma. The orange line indicates high HLA class I expression, the green line indicates low HLA class I expression, and the blue line indicates negative HLA class I expression. Patients with high HLA class I expression at the invasive front (IF) showed better OS than those with low or negative expression. However, there was no difference in OS based on HLA class I expression in the tumor center (TCe)