The exposure of mussels to metallic nanoparticles of cadmium (Quantum dots) induces changes in the metallothionein gene (mt20IV) indicating a specific response of this gene in the metabolism and a protection against oxidative stress caused by the accumulation of Quatum dots in mussel tissues. These results are presented in the publication "Changes in metallothionein transcription levels in the mussel Mytilus galloprovincialis exposed to CdTe quantum dots" by Thiago Lopes Rocha, Eider Bilbao, Cátia Cardoso, Manu Soto and Maria João Bebianno published online in the journal Ecotoxicology.