The expression of TβRI, TβRII and TβRIII in human oral squamous carcinoma. TβRI in OSCC tissues and in OLK showed the same homogeneous, moderate, and intense cytoplasmic expression as in normal oral specimens (A-D). IHC analysis showed that the expression of TβRII (E-H) and TβRIII (I-L) decreased gradually with the progression of carcinogenesis. (E) Strong signal for TβRII was detected in the upper spinous and granular layers of normal specimens. (F) Positive staining was detected mainly in the granular layers and in cuticular layer (arrowhead) in OLK without dysplasia. (G) The immunostaining profile was decreased in OLK with dysplasia. (H) Significant downregulation of TβRII was observed in infiltrated OSCC. (I) Strong signal for TβRIII was detected in the basal layer and in the upper spinous in normal specimens (arrowhead). (J) Positive staining was significantly decreased in OLK without dysplasia and a stronger signal for TβRIII was detected in the basal layer. (K) The immunostaining profile was decreased in OLK with dysplasia. (L) Note the absence of TβRIII staining in OSCC tissues. Weak expression of TβRIII was observed in OSCC stroma exclusively. (F) IHC scores for TβRI in patient-matched normal and OSCC samples.