CCL18 and head and neck squamous cell carcinoma: Subsequently, ELISA results showed that the serum levels of CCL18 in SCCHN patients were 42134 ± 2245 pg/mL, while those of precancerous lesions of SCCHN patients and healthy donors were 28945 ± 2851 and 22551 ± 1544 pg/mL respectively (P < 0.0001) (Figure 1A).