Fig. 1.

Evaluation of CDK9 expression and staining in an osteosarcoma TMA by immunohistochemistry. (A) Representative images of different immunohistochemistry staining intensities of CDK9 and HE staining are shown in osteosarcoma tissues. According to the CDK9 staining in the tumor samples, the staining patterns were divided into 6 groups: no positive staining (0); <10% positive cells (1+); 10–25% positive cells (2+); 26–50% positive cells (3+); 51–75% positive cells (4+); >75% positive cells (5+). (Original magnification, 400×; Scale bar, 50 μm). (B) Pie chart representing relative frequency of different CDK9 expression levels in osteosarcoma tissue microarrays. (C) Tumors with the staining score of ≤2+ were defined as low CDK9 expression group (blue), ≥3+ were defined as the high CDK9 expression group (green). Pie chart representing relative frequency of the two groups in osteosarcoma tissue microarrays.