The CIBERSORT algorithm revealed significant differences in the infiltration of various immune cell types, including CD8+ T cells, follicular helper T cells, activated NK cells, resting NK cells, resting memory CD4+ T cells, memory B cells, regulatory T cells (Tregs), naive B cells, gamma delta T cells, and neutrophils between the C1 and C2 HNSCC subtypes (Figure 8A). Here, CD4 is linked to head and neck squamous cell carcinoma.