Knockdown of PC4 expression by sequence-specific small interfering RNA in human NSCLC cells and in pre-established NSCLC cell xenografts in mice showed significant inhibition on growth of tumor cells and tumor, respectively, suggesting that PC4, a validated novel cancer biomarker, could be a potential therapeutic target for the treatment of NSCLC [18, 22]. This evidence concerns the gene SUB1 and neoplasm.