ULBP2 and neoplasm: We found that serum ULBP2 levels were significantly higher in patients with early-stage primary tumors (205.7±184.3 pg/mL, p<0.0001, n = 34), no lymph node metastasis (191.6±155.2 pg/mL, p<0.0001, n = 57), and at an early overall tumor stage (181.2±158.8 pg/mL, p<0.0001, n = 106) than in healthy controls (51.4±64.6 pg/mL; n = 142; Fig. 4A).