Despite all limitations and difficulties involved in the analysis of immune cells and especially the interpretation of the data, the consideration of this complex topic may provide relevant links to other related topics, such as the oncologic outcome of patients with head and neck cancer (54), which could be further investigated with markers expressed on immune cells (e.g., PD-1/PD-L1; 21, 43, 55). Here, CD274 is linked to head and neck cancer.