ITGAL and head and neck squamous cell carcinoma: As per the cohort of Hwang 2020, we also found that the efficacy of Anti-PD-1 monotherapy on HNSCC was closely related to the ITGAL expression, and those with high ITGAL expression were more likely to respond to Anti-PD-1 (Figure 13D), and the probability was as high as 76.9% (Figure 13E).