FIG. 9.

Rap1GAP protein expression is decreased in primary thyroid tumors. Five classic papillary thyroid carcinomas were stained for Rap1GAP (see Materials and Methods). (A) Low-power fields showing that Rap1GAP is expressed in follicular epithelial cells (normal cells [NC]) and tumor cells (TC) but not in stromal cells (SC), endothelial cells (EC) (see B), or lymphocytes (LC). (B and C) High-power fields of normal thyroid tissue (B) versus tumor tissue from the same section (C). Rap1GAP expression was consistently decreased in tumor cells versus adjacent normal cells in the same sections. The scoring results from five samples are summarized in panel D.