Fig. 2
Meta-analysis based on GEO datasets. a Forest plot for the integrated standard mean deviation, which was 1.52 (95%: 0.96, 2.08) and had obvious heterogeneity (I2 = 83.5%, p = 0.000), showing that miR-221-3p content was significantly decreased in pancreatic cancer. b Sensitivity assessment of microarrays. c Inspection of publication bias with a funnel plot (Begg’s test, p = 0.077). d Subgroup analysis divided by sample origin. Both the serum groups and tissue groups had great heterogeneity. e Subgroups analysis divided by pathological subtype. Both the pancreatic ductal adenocarcinoma and uncertain carcinoma subgroups had great heterogeneity