MKI67 and B-cell non-Hodgkin lymphoma: ROC curve analysis established 48.7% as the cut-off value for MFC to distinguishing aggressive large B cell lymphoma from transformed B cell lymphoma (area under the curve =0.742, P < 0.001); Therefore, when this value was used, the positive rates of Ki67 expression could identify transformed B cell lymphoma with a sensitivity of 76.2% and a specificity of 65.3% (Figure 4B).