NAMPT and neoplasm: Median [IQR] serum visfatin levels were higher in patients with NETs regardless of tumor’s primary site (6.94 [2.11–236.17] ng/mL, p = 0.004) as well as when stratified by panNETs (4.98 [2.13–264.96] ng/mL, p = 0.019) and siNETs (7.46 [2.01–199.44] ng/mL, p = 0.007) vs. controls (1.59 [1.1–9.24] ng/mL).