Figure 1: Representative immunohistochemical staining of markers HIF-1α, PDK-1 and mTOR. Variable expression of HIF-1α is illustrated by a poorly differentiated tumor (A) with negative to focally weak (1+) staining and a second tumor (B) with moderate (2+) staining of nuclei and cytoplasm. Similarly, PDK-1 staining in two tumors ranges from negative (C) to patchy and focally strong (3+) cytoplasmic expression (D). While one tumor (E) shows patchy and weak (1+) staining for mTOR, another (F) shows strong (3+) expression.