Table 2. Association between ubiquitin-specific protease 22 expression and various clinicopathological factors of patients with non-small cell lung cancer.

Variables	Categories	Cases	USP22 protein expression		P value
		(n=86)	Low (n=47)	High (n=39)
Age	<60	44	27 (61.4%)	17 (38.6%)	NS
	≥60	42	20 (47.6%)	22 (52.4%)
Gender	Male	57	31 (54.4%)	26 (45.6%)	NS
	Female	29	16 (55.2%)	13 (44.8%)
Smoking history	Non-smoker	29	15 (51.7%)	14 (48.3%)	NS
	Smoker	57	32 (56.1%)	25 (43.9%)
Histological type	Scc	31	18 (58.1%)	13 (41.9%)	NS
	Ac	49	25 (51.0%)	24 (49.0%)
	Others	6	4 (66.7%)	2 (33.3%)
Tumor differentiation	Well	6	1 (16.7%)	5 (83.3%)	NS
	Moderate	47	24 (51.1%)	23 (48.9%)
	Poor	33	22 (66.7%)	11 (33.3%)
TNM stage	I	55	32 (58.2%)	23 (41.8%)	NS
	II	31	15 (48.4%)	16 (51.6%)
Tumor size	≤3 cm	42	28 (66.7%)	14 (33.3%)	0.029
	>3 cm	44	19 (43.2%)	25 (56.8%)
Lymph node metastasis	Absent	57	36 (63.2%)	21 (36.8%)	0.026
	Present	29	11 (37.9%)	18 (62.1%)

USP22, ubiquitin-specific protease 22; NS, not significant; SCC, squamous cell carcinomas; AC, adenocarcinomas; TNM, tumor-nodes-metastasis.