Hence, CARNIVAL was able to construct a signalling network highly enriched for HER2 signalling, including the signalling proteins MAPKs, ESR1, ERBB2, EGFR, PIK3CA [52] and EP300 [53], which are known to be relevant for the primary mechanism of action of lapatinib in HER2 + cancers [52]. This evidence concerns the gene PIK3CA and cancer.