Fig 2: The expression levels of NRDC. (A) Serum NRDC levels in control group and PDAC different staging groups. HC (n = 61), BDG (n = 31), and PDAC including I/II (n = 63), III/IV (n = 48). (B) Serum NRDC levels in various differentiation groups, well-moderated group (n = 58), poor differentiation group (n = 25). (C) Relative mRNA expression levels in cell lines, all PDAC cell lines were compared to the normal pancreatic cell lines. The procedure was repeated three times, consistent with the previous results. (D) Relative mRNA expression levels in two patients, Cancer-1/2 were from two different patients’ cancer tissues, Normal-1/2 were from patients’ peritumoral tissues. The procedure was repeated three times in six patients’ tissues, consistent with the previous results. * p < 0.05, *** p < 0.001, and **** p < 0.0001. ns: none significance, HC: healthy control, BDG: benign disease group.

Fig 3: Gene set enrichment analysis (GSEA) of NRDC, (A–F) different signal pathway enrichment of NRDC, curves marked with green flag mean gene enrichment. Peaks on the upward curve indicate positive correlation. (G) according to the average expression of NRDC, divided genes into high and low groups, heatmap of the top 40 differentially expressed genes in the analysis result (Red: up-regulation; Blue: down-regulation), (H) divided the expression of NRDC into high and low groups, volcano plot of differential genes were expressed (logFC = 0.4 and -log10 (adj. p Value) = 1 were defined as significance. Red: up-regulation; Blue: down-regulation).

Fig 4: Results of gene ontology (GO) enrichment analysis of NRDC in GSE102238. (A) Biological process categories of enriched terms. (B) Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis of NRDC, printed by p-values and gene counts. (C) The expression of NRDC in different cancer types. Bar plots profiling gene expression between tumor samples (red) and paired normal samples (blue). (BLCA: bladder urothelial carcinoma; BRCA: breast invasive carcinoma; CHOL: cholangiocarcinoma, COAD: colon adenocarcinoma; ESCA: esophageal carcinoma; GBM: glioblastoma multiforme; HNSC: head and neck squamous cell carcinoma; KICH: kidney chromophobe; KIRC: kidney renal clear cell carcinoma; KIRP: kidney renal papillary cell carcinoma; LIHC: liver hepatocellular carcinoma; LUAD: lung adenocarcinoma; LUSC: lung squamous cell carcinoma; PRAD: prostate adenocarcinoma; READ: rectum adenocarcinoma; STAD: stomach adenocarcinoma; THCA: thyroid carcinoma; UCEC: uterine corpus endometrial carcinoma; **: p < 0.01; ***: p < 0.001).

Fig 5: Immunohistochemistry (IHC) staining tissues of NRDC in pancreatic ductal adenocarcinoma. (A) Expression of NRDC protein in human pancreatic normal tissue (n = 6). (B) The overview of IHC in cancer and normal tissue. (C) H&E staining of human pancreatic ductal adenocarcinoma and normal tissue. (D) Expression of NRDC protein in human pancreatic ductal adenocarcinoma tissue (n = 9).