FGFR2 and neoplasm: On the other hand, the use of “in vitro” models has been particularly appropriated for the demonstration of the key role of KGFR as a tumour suppressor controlling epithelial cell differentiation: in fact, several studies have demonstrated that the re-expression of KGFR in cultured cells from epithelial tumours in which this receptor is down-regulated was able to inhibit cell growth and to induce differentiation [10]–[14].