Expression of Smad4 and TGF-beta2 in colorectal carcinoma.

Abstract

In poorly-differentiated carcinoma, Smad4 protein expression was retained and may be linked to TGF-beta2 overexpression, due to the activation or deregulation of the TGF-fl signalling pathway. Inactivation of the TGF-beta gene occurs at an early stage of colorectal carcinogenesis, while inactivation of Smad4 is probably a late event.