PHLDB2 and head and neck squamous cell carcinoma: Interestingly, a significant negative correlation was observed between the expression of PHLDB2 and the infiltration of multiple immune cells in HNSCC, particularly cytotoxic cells (r = −0.440, p < 0.001) and T cells (r = −0.364, p < 0.001) (Figure 4C,D).