CD9 and malignant epithelioid mesothelioma: Hence, we performed multivariate analysis of patients with epithelioid mesothelioma alone and we again found that CD9 expression was a predictor of survival of mesothelioma patients with an HR of 2.60 (P=0.0376) (Table V), suggesting the independent prognostic value of CD9 expression in mesothelioma.