Our study demonstrates that USP22 is highly expressed in NSCLC tissues and plays an important part in NSCLC tumorigenesis, which is consistent with the results obtained from different tumors, such as colorectal carcinoma [11], bladder cancer [13] and prostate adenocarcinoma [37], and contributes to NSCLC tumorigenesis through up-regulating MDMX and subsequently suppressing the p53 pathway. This evidence concerns the gene TP53 and non-small cell lung carcinoma.