The present invention relates to the use of PDGF receptor tyrosine kinase or bcr-abl tyrosine kinase inhibitors, especially of N-phenyl-2-pyrimidine-amine derivatives of formula I, in which the symbols and substituents have the meaning as defined herein in free form or in pharmaceutically acceptable salt form, in the manufacture of a pharmaceutical composition for the treatment of tuberous sclerosis associated neoplasms; to a method of treatment of warm-blooded animals, including humans, suffering from a tuberous sclerosis associated neoplasms.