In addition, logistic regression analysis showed that the radiographic sign (liquefaction necrosis) was an independent predictor of Ki­67 high expression in pure-solid NSCLC, and this may be explained by the fact that these radiographic signs always appear on CT scans of lesions containing fast-growing tumor cells, characterized by high Ki-67 levels. The gene discussed is MKI67; the disease is non-small cell lung carcinoma.