Table 1. The datasets characteristic of nine microarray chips.

GEO accession	Platform of dataset	Region	Submission year	Type of platform	Sample	All miRNAs	DEMs	References
GSE23739	GPL7731	Switzerland	2011	Agilent-019118 Human miRNA Microarray 2.0 G4470B	40 paired of GC vs. GNT	720	122	Oh HK
GSE26595	GPL8179	South Korea	2011	Illumina Human v2 MicroRNA expression beadchip	60 paired of GC vs. GNT	360	5	Lim JY
GSE26645	GPL11487	China	2011	Agilent-021827 Human miRNA Microarray	4 paired of GC vs. ANT	851	3	–
GSE28700	GPL9081	Taiwan	2011	Agilent-016436 Human miRNA Microarray 1.0 G4472A	22 paired of GC vs. GNT	470	25	–
GSE33743	GPL14895	Portugal	2011	miRNAChip_human_V2	37 primary GC vs. 10 GNT	703	7	Carvalho J
GSE54397	GPL15159	South Korea	2014	Agilent-031181 Unrestricted_Human_miRNA_V16.0_Microarray 030840	16 paired of GC vs. GNT	1205	50	Chang H
GSE63121	GPL8786	China	2014	Affymetrix Multispecies miRNA-1 Array	15 paired of GC vs. GNT	848	24	Zhang X
GSE78091	GPL21439	China	2016	miRCURY LNA microRNA Array, 7th generation - hsa, mmu & rno	3 paired of GC vs. GNT	1,921	385	–
GSE93415	GPL19071	Poland	2017	Exiqon miRCURY LNA microRNA array; 7th generation REV - hsa, mmu & rno; batch 208520-22; lot 35101-35101	20 paired of GC vs. ANT	891	107	–

GEO, Gene Expression Omnibus; DEMs, differentially expressed miRNAs; GC, gastric cancer; GNT, gastric normal tissue; ANT, adjacent normal tissue; LNA, Locked Nucleic Acid; REV, Revision.