PIK3CA and neoplasm: In the HM tumours, genes mutated in more than 20% of the cases belonged to the TGFβ–BMP, WNT, RTK–RAS, ribosomal proteins, epigenetic regulation, PI3K, SCF complex, p53 and immune system pathways, and the most frequently recurring mutations were in ACVR2A (p.K437Rfs*5; 78%), BRAF (p.V600E; 65%) and RNF43 (p.G659Vfs*41; 57%).