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e Summary. cell migration and invasion are crucial steps in many physiological events. However, they are also implicated in the physiopathology of many diseases, such as cancer. to spread through the tissues, tumor cells use mechanisms that involve several molecular actors: adhesion receptor fami-lies, receptor tyrosine kinases, cytoskeleton proteins, adapter and signalling proteins interplay in a complex scenario. the balance of cellular signals for proliferation and survival responses also regu-lates migratory behaviours of tumor cells. to complicate the scene of crime drug resistance players can interfere thus worsening this delicate situation. the complete understanding of this molecular jungle is an impossible mission: some molecular aspects are reviewed in this paper. Key words: neoplasms, neoplasm invasion, molecular markers. Riassunto (Aspetti molecolari della migrazione ed invasione delle cellule tumorali). La migrazione e l’invasione cellulare rappresentano momenti cruciali in molti eventi fisiologici: questi due processi, tuttavia, sono anche implicati nella fisiopatologia di varie malattie, tra cui i tumori. Per diffonder-si attraverso i tessuti, le cellule tumorali ricorrono a meccanismi che vedono il coinvolgimento di diversi componenti cellulari: famiglie di molecole di adesione, recettori tirosinchinasi, proteine de