Staining intensity of phosphorylated STAT-3 and STAT-5 (pSTAT-3 and pSTAT-5, respectively). pSTAT-3 staining was scored 0 if fewer than 10 positive nuclei were present in high magnification field (400×); 1+ if 10 to 20 positive nuclei were present; 2+ if 21 to 40 positive nuclei were present; and 3+ if more than 40 positive nuclei were present. pSTAT-5 staining was scored 0 if 0 to 1 positive nucleus were present in high magnification field; 1+ if 2 to 4 positive nuclei were present; 2+ if 5 to 9 positive nuclei were present; and 3+ if more than 10 positive nuclei were found. For each slide, a minimum of 10 high-magnification fields were examined (avidin-biotin complex immunoperoxidase method: original magnification, 400×).