PIK3CA and neoplasm: A gene set enrichment analysis (http://software.broadinstitute.org/gsea/login.jsp) of the mutated genes (only genes with a frequency of >20%) for each sample confirmed that the main processes altered in these tumor cells were related to genomic instability and the deregulation of different mechanisms that are relevant to several signaling pathways, such as the RAS, PI3K and c-KIT pathways (Figure 3C).