The present invention relates to an RNAi molecule suitable for reducing the expression of galectin-1 containing any of the sequences of SEQ ID NOs: 1-33, and preferably the sequences of SEQ ID NO: 2, 3, or 4, and to the use thereof as a medicament, or for the manufacture of a medicament for treating and/or for delaying the progression of cancer, preferably glioma, pancreatic cancer, head and neck cancer, melanoma, non-small-cell lung cancer and non-Hodgkin's lymphoma. The present invention also relates to compositions and methods for treating and for delaying the progression of cancer, preferably glioma, pancreatic cancer, head and neck cancer, melanoma, non-small-cell lung cancer and non-Hodgkin's lymphoma, for reducing the migration of tumor cells, preferably cells of glioma, pancreatic cancer, head and neck cancer, melanoma, non-small-cell lung cancer and non-Hodgkin's lymphoma, and/or for enhancing the efficacy of cancer therapies for the treatment of cancer, preferably glioma, pancreatic cancer, head and neck cancer, melanoma, non-small-cell lung cancer and non-Hodgkin's lymphoma, selected from the group comprising chemotherapy, radiation therapy, immunotherapy, and/or gene therapy.
