PIK3R1 and neoplasm: As an illustration, somatic alterations, including chr4:153249510 (FBXW7), chr5:67591246 (PIK3R1), rs28934576 and rs11540652 (TP53), rs121913399 (CTNNB1), and chr19:52716323 (PPP2R1A), were specifically enriched in cluster 2, which was linked to higher tumor aggression and poor prognoses.