The present invention is related to an inhibitor of the inositol
polyphosphate 5-phosphatase SHIP2 protein or its encoding nucleotide
sequence identified by SEQ ID NO. 1 or of SHIP2 mRNA expression. The
present invention is also related to a pharmaceutical composition
comprising said inhibitor and an adequate pharmaceutically acceptable
carrier or diluent and to a non-human knock-out mammal comprising
homozygously or heterozygously a partial or total deletion in its genome
of the inositol polyphoshate 5-phosphatase SHIP2 nucleotide sequence.