We previously described the generation of three autochthonous models of sarcoma via intramuscular injection of concentrated ecotropic MuLE lentiviruses expressing either shRNA-Cdkn2a + HrasG12V, shRNA-Trp53 + HrasG12V or shRNA-Trp53 + shRNA-Pten + HrasG12V in SCID/Beige mice [34]. Here, PTEN is linked to sarcoma.