The ROC curve analysis established 7.65% as the cut-off value for MFC to distinguishing indolent from transformed B cell lymphoma (area under the curve =0.915, 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 90.5% and a specificity of 87.6% (Figure 4A). The gene discussed is MKI67; the disease is B-cell non-Hodgkin lymphoma.