Figure 2.

Immunohistochemical staining of adenocarcinoma tissue sections demonstrating STAT3 expression (magnification, ×200). (A) Adenocarcinoma specimen demonstrating high expression of STAT3-positive tumor cells (score 3). (B) Adenocarcinoma specimen demonstrating moderate expression of STAT3-positive tumor cells (score 2). (C) Adenocarcinoma a specimen demonstrating low expression of STAT3-positive tumor cells (scores 1). (D) Photomicrographs of a corresponding normal lung tissue specimen with no STAT3-positive tumor cells (score 0). STAT3, signal transducer and activator of transcription 3.