Tumorigenicity decrease in Bcl-xL deficient MDCK cells ensuring the safety for influenza vaccine production - Jiahao Zheng; Boran Li; Lanxin Jia; Jiayou Zhang; Zheng Gong; Yang Le; Xuanxuan Nian; Xuedan Li; Bo Liu; Daiguan Yu; Zhegang Zhang; Changgui Li (PLoS ONE)