MKI67 and pancreatic adenocarcinoma: The relationship between PLAGL1 and MKI67 expression levels also confirmed that the mRNA expression level of PLAGL1 was negatively correlated with MKI67 mRNA expression levels in the TCGA-PAAD cohort, GSE28735 cohort and our PAAD verification cohort 1 (Fig. 2d–f).