PIK3CA and neoplasm: Importantly, two PROG lesions with no identified MAPK activating mutations, but with acquired PROG-specific PI3K/AKT-activating alterations showed MAPK activity restoration to pre-treatment tumour levels; Pt9-DP1 (PIK3CAD350G,E545G;16) and Pt13-DP1 (AKT1Q79K;4,5) (Fig. 1b).