LCN2 and appendicitis: In addition to standard biomarkers several new biomarkers for AA such as hyponatremia [18,23], hyperfibrinogenemia [23], hyperbilirubinemia [22], leucine-rich α-2-glycoprotein 1 [21], neutrophil gelatinase-associated lipocalin (NGAL) [24], or interleukin-6 (IL-6) [19,24] have been recently investigated and presented good predictive values for the detection of acute appendicitis, as well as for distinguishing between complicated and simple AA.