In 2018, thyroid cancer affected 130,889 new cases in males and 436,344 new cases in females, and the incidence rate in females is more than 3 times higher than in males [
1]. Papillary thyroid carcinoma (PTC) is the most common type of thyroid cancer [
2]. PTC is a type of slow-growing, well-differentiated, and localized thyroid cancer, although it can metastasize [
2]. Comparing to other malignancies mortality rate of thyroid cancer is relatively low, which is mainly due to its less aggressive nature and slow development [
3]. In 2018, thyroid cancer only caused 41,000 deaths, which is only about 7% of the newly diagnosed cases [
1]. However, metastasis will inevitably occur in some cases of PTC, leading to poor prognosis [
4,
5]. Therefore, early diagnosis is still critical. However, PTC in some cases can be misdiagnosed as other thyroid disorders, such as benign thyroid nodules [
6]. Therefore, how to distinguish PTC from BTN is a challenge in clinical treatment.
Taking advantage of the non-invasive nature, circulating markers have been widely used for disease prediction [
7]. Long no-coding RNAs (> 200 nt, lncRNAs) are RNA transcripts encoding no protein [
8]. However, lncRNAs can regulate the expression of protein-coding genes at multiple levels to participate in diverse pathological and physiological processes [
8]. Although lncRNAs are usually spatially and/or temporally expressed, they can be released into blood circulation system after synthesis to traffic to other positions of the body [
9,
10]. Therefore, the dysregulation of lncRNAs under pathological conditions may be reflected by its levels in plasma [
9,
10]. DLG1-AS1 is a recently identified oncogenic lncRNA in cervical cancer [
11]. MiR-199a-3p is a well-characterized tumor suppressive miRNA in cancer biology [
12‐
14]. We observed the inverse correlation between DLG1-AS1 and miR-199a-3p from our preliminary bioinformatics analysis. This study aimed to explore the roles of DLG1-AS1 and miR-199a-3p in PTC and analyze the clinical values of DLG1-AS1 for this disease.