CHI3L1 and periodontal disorder: Several other components of GCF are also shown to reflect the periodontal disease status that includes neutrophil elastase [42], periostin [43], Chitinase-3-like protein 1 (also known as YKL-40) [44], lysophosphatidic acid (LPA) [45], human beta-defensins (hBDs) [46], hypoxia-inducible factor-1α (HIF-1α) [47], osteoprotegerin [48], and anti-Hsp-70 (heat shock protein family A) [49].