AKT1 and gastrointestinal stromal tumor: In this study, we investigate the prognostic impact of all isoforms of Akt (phosphorylated at threonine 308 and Akt phosphorylated at serine 473, non-phosphorylated Akt2, and total Akt3), PI3K, PTEN, ER and PgR in 249 non-GIST STS patients.