The present invention relates to improved treatments of cancer resistant to a molecule of the taxoid family. It also relates to methods for selecting a patient affected with a tumor for a treatment with a molecule of the taxoid family in combination with a compound inhibiting the TGF-β signalling pathway or for determining whether a patient affected with a tumor is susceptible to benefit from a treatment with a molecule of the taxoid family in combination with a compound inhibiting the TGF-β signalling pathway as well as methods for screening or identifying a compound suitable for improving the treatment of a cancer with a molecule of the taxoid family or for reducing the resistance development during the treatment. The invention also relates to kits for performing these methods.