The combination of GDC-0575 with gemcitabine demonstrated a synergistic antitumor effect and improved survival in dedifferentiated liposarcoma and leiomyosarcoma xenografts and TP53 mutant PDX models with the combination therapy, compared to either agent alone (no reduction was observed in the TP53 wild type PDX model) [112]. The gene discussed is TP53; the disease is liposarcoma.