To examine whether inhibition of AKT signaling potentiates the cytotoxic activities of Dox in STS and GIST, we performed MTS-based survival assay with a broad spectrum of cancer cell lines, including SK-LMS-1 leiomyosarcoma, RD rhabdomyosarcoma, HT-1080 fibrosarcoma, A673 Ewing’s sarcoma, U2-OS osteosarcoma, IM-sensitive and resistant gastrointestinal stromal tumors (e.g., GIST T-1 vs. GIST T-1R and GIST 430, respectively). This evidence concerns the gene AKT1 and fibrosarcoma.