The present invention generally relates to the field of molecular biology and RNA interference (RNAi). More specifically, the present invention relates to specific siRNA molecules, compositions and uses thereof, as well as methods of treating cancer and methods of inhibiting cancer cell proliferation, particularly methods of treating breast cancer. Yet more particularly, the methods of the present invention are methods for inhibiting growth of triple negative breast cancer (TNBC). In a preferred embodiment, the invention provides specific siRNA molecules, comprising a sequence selected from SEQ ID NO: 1 and SEQ ID NO: 2, and from any other sequence having a sequence identity greater than 90% between the siRNA and the portion of the target gene. Such siRNA molecules are suitable for the treatment of breast cancer, particularly, TNBC.