Figure 4. Correlations of VRK1 expression with TME biomarkers. (A) The heatmap depicts the relationships between VRK1 expression and the 47 different types of immune regulators in various cancers by Spearman correlation analysis. (B) Correlations between VRK1 expression and tumor mutation burden (TMB) across cancers. (C) Correlations between VRK1 expression and microsatellite instability (MSI) across cancers. (D) Correlation between VRK1 expression level and the expression of five MMR genes. The left bottom triangle in each unit represents Pearson’s correlation test coefficient of association. (E) Correlation between VRK1 expression level and four methyltransferase genes. (*P < 0.05, **P < 0.01, and ***P < 0.001).