Table 4. Candidate miRNAs for detecting pancreatic malignancy in EUS-FNAs.

miRNA	Relevance in pancreatic disease	Target genes in PDAC	References
miR-21-5p	Up-regulated in PDAC. Associated with poor prognosis. Enhances resistance to gemcitabine. Up-regulated in non-invasive IPMNs and CEIs.	BTG2, PDCD4, PTEN, SPRY2, RECK, BCL2	[13, 16, 29, 30, 36]
miR-10b-5p	Up-regulated in PDAC. Associated with poor prognosis.	HOXD10, KLF4, TIAM1	[17, 30]
miR-155-5p	Up-regulated in PDAC. Associated with poor prognosis. Up-regulated in non-invasive IPMNs and CEIs.	TP53INP1, FOXP3, PIK3R1	[16, 29, 30]
miR-196a-5p	Up-regulated in PDAC. When normalised with miR-217 (i.e. miR-196a/217), able to detect PDAC with AUC of 0.76 and 0.78.	HOXB8, HMGA2, Annexin A1	[15, 20, 30]
miR-217	Down-regulated in PDAC.	KRAS	[29]
miR-210-5p	Up-regulated in PDAC. Able to detect PDAC with AUC of 0.76. Raised circulating levels in PDAC. Associated with poor prognosis.	EFNA3	[15, 37, 38]
miR-135b-5p	When normalised with miR-24 (i.e. miR-135b/24), able to distinguish PDAC from CP with sensitivity & specificity of 93% and AUC 0.97.	Adenomatous Polyposis Coli in CRC	[15]
miR-24-3p	No specific role in PDAC known. Found to be stably expressed at relatively high levels in all pancreatic cell types. Used for miR-135b/24 classifier.	Member of miR-23a ~ 27a ~ 24–2 cluster and may have overlapping targets	[15]

EUS-FNA, endoscopic ultrasound fine-needle aspiration; IPMN, intraductal papillary mucinous neoplasm; PDAC, pancreatic ductal adenocarcinoma; CEI, carcinoma-ex-IPMN (i.e. invasive IPMN); CP, chronic pancreatitis; CRC, colorectal cancer; AUC, area under the curve.