Table 1.

Differences in PEDF expression between melanocytes and melanoma cell line collections and within melanoma cell line collections

a. Differences in PEDF expression between melanocyte and melanoma cell line collections.
Data set	Average		S.D.		Fold	Statistical test
Melanocyte	3.58		3.25
Mannheim	1.45		1.98		2.48	Mann-Whitney, p<0.001
Melanocyte	3.44		3.13
Philadelphia	0.84		1.22		4.10	Mann-Whitney, p<0.0001
Melanocyte	5.47		4.97
Johansson	2.63		5.03		2.08	Mann-Whitney, p<0.0001
Melanocyte	2.27		2.06
Wagner	0.61		0.82		3.75	Mann-Whitney, p<0.001
b. Differences in PEDF expression between weakly and strongly invasive cohorts of melanoma cell lines.
Data set	Weakly invasive		Strongly invasive		Fold	Statistical test
	Average	S.D.	Average	S.D.
Mannheim	4.74	4.67	1.05	1.59	4.50	Mann-Whitney, p<0.05
Philadelphia	4.99	5.94	2.16	4.58	2.31	Mann-Whitney, p<0.05
Johansson	8.21	15.48	3.11	6.27	2.64	Mann-Whitney, not significant (p=0.14)
Wagner	2.65	2.79	1.48	2.31	1.78	t-test, not significant (p=0.42)

Note: while “Melanocyte” refers to the same collection of cultures in each case, the normalized expression measurement is affected by the melanoma cell line data set with which it is normalized and therefore the average value for PEDF should not be expected to remain static.