SELL and neoplasm: Further, the circulating levels of TNF-α showed a significant positive correlation with the circulating levels of L-Selectin (r = +0.303, P = 0.005), while the protein expression of TNF-α (r = +0.347, P = 0.001) showed a significant positive correlation with VCAM-1 expression in the primary tumours of PTC patients (Table 6).