CXCR4 and head and neck squamous cell carcinoma: The depth of the tumor invasions showed a statistically significant increase in the groups with both the IL-33-overexpressing stable clones in sections of the matrix layer with embedded CAFs compared to the conditioned groups of the IL-33-overexpressing stable clones following blockages of IL-33 or CXCR4, which showed less invasion depth in the HNSCC cells.