TUG1 and osteosarcoma: Some lncRNAs were also highlighted as circulating biomarkers due to their stability, significantly higher expression in body fluids (especially in serum/plasma of osteosarcoma patients) and their correlation to disease stage or metastatic potential; for example, lncRNA TUG1, UCA1, HNF1A-AS1, MALAT-1, FAL-1 and ATB, etc. (Botti et al., 2019).