Table 1. Correlations between p-ERK and ERK expression and various clinicopathologic parameters in ESCC.

Parameter		Case NO.	low/high expression
			p-ERK	ERK
Age	≤ 57	66	38/28	20/46
	> 58	65	27/38	20/45
Gender	Male	98	48/50	31/67
	Female	33	17/16	9/24
Tumor site	Upper	13	4/9	3/10
	Middle	104	54/50	33/71
	Lower	14	7/7	4/10
Differentiation	Poor	12	4/8*0.04	2/10*0.012
	Intermediate	75	37/38	20/55
	Well	44	30/14	18/16
Tumor size	> 5 cm	82	40/42	25/57
	< 5 cm	49	25/24	15/34
Depth of invasion	T1–T2	103	55/48	28/75
	T3–T4	28	10/18	12/16
Lymph metastasis	Yes	68	31/37	18/50
	No	63	34/29	22/41
Clinical Stage	1	6	4/2*0.02	5/1*0.031
	2	55	35/20	17/38
	3	64	25/39	17/47
	4	6	1/5	1/5

^* p < 0.05.