Cell adhesion in tumors............................................. 1.1. Invasive carcinoma cells exhibit reduced intercellular adhesion.................... 1.2. The role of the cell adhesion molecule E-cadherin........................... 1.3. Other mechanisms for epithelial to mesenchymal conversions in carcinomas............ 1.4. Cell adhesion dynamics in metastasis formation............................ 2. The structure of cell-cell adherens junctions................................. 2.1. Possible defects of cell adhesion components in carcinoma cells................... 2.2. Control of expression of junctional components............................ 3. The role of paracrine factors.......................................... 3.1. Mesenchymal-epithelial interactions................................... 3.2. Epithelial motility factors: the role of scatter factor/hepatocyte growth factor........... 4. Cadherin expression in various tumors.................................... 4.1. E-cadherin expression in squamous cell carcinomas of the skin.................... 4.2. E-cadherin expression in squamous cell carcinoma of head and neck................ 4.3. E-cadherin expressmn in breast adenocarcinomas........................... 4.4. E-cadherin expression in colorectal carcinomas............................. 4.5. E-cadherin expression in gastric adenocarcinomas........................... 4.6. E-cadherin expressmn in prostate adenocarcinomas.......................... 4.7. E-cadherin expression in other types of human carcinomas...................... 5. Conclusions and perspectives.......................................... Acknowledgements................................................. References......................................................