To have a base for inferring the response of STS to Dinaciclib, we analyzed the expression of CDK9, CDK1 and its partners Cyclin B1 and A2 in a series of cell lines representative of major groups of STS: synovial sarcoma SW982 and 1273–99, leiomyosarcoma SK-LMS-1 and SK-UT-1, myxoid liposarcoma 402–91 and 1765–92, dedifferentiated liposarcoma SW872 and myxofibrosarcoma HT-1080 (Fig. 1A). This evidence concerns the gene CDK9 and leiomyosarcoma.