PIK3R1 and neoplasm: This TMPRSS2-ERG positive tumour is characterised by a high PGA at 26%, pathogenic somatic SNV in TP53 (rs28934575, c.733G > A; p.Gly245Ser), as well as copy number loss of PTEN. Additional losses in MAP3K1, PIK3R1 and TP53 were observed, along with somatic alterations in the MAPK and PI3K pathways (Figure 5).