GSEA on differentially methylated CpGs in promoter regions of Cluster 1A tumours revealed very similar results to the over-representation analysis and included the terms extracellular matrix organisation, the L1 family of cell adhesion molecules (L1CAMs) interactions, signalling by RTK, VEGF signalling and Rho GTPase cycling (Fig. 2D). This evidence concerns the gene VEGFA and neoplasm.