Table 2. Statistical analysis of $\overline{CI}$ and Δ$\overline{CI}$ values for overexpressed eGFP-ERK2, endogenous ERK1/2 and rERK2-LOC, 15 min after serum or FGF4 stimulation.

	Treatments	$\overline{CI}$	n	S	p value	Fold-change	Δ$\overline{CI}$	Ratio rERK2-LOC / IF:ERK1/2
eGFP-rERK2	Baseline	0.586 ± 0.024	10
	Serum	0.692 ± 0.083	5	ns	0.4658	1.18
	FGF4	0.643 ± 0.050	6	ns	0.9065	1.10
	U0126	0.659 ± 0.054	8	ns	0.6977	1.13
	U0126 + serum	0.767 ± 0.043	6	*	0.0355	1.31
	U0126 + FGF4	0.598 ± 0.019	11	ns	0.9997	1.02
	DMSO + serum	0.759 ± 0.068	7	*	0.0353	1.30
	DMSO + FGF4	0.701 ± 0.036	10	ns	0.1933	1.20
IF:ERK1/2	Baseline	0.200 ± 0.009	16
	Serum	0.273 ± 0.007	9	***	0.0003	1.37	0.073 ± 0.011
	FGF4	0.291 ± 0.008	27	****	< 0.0001	1.46	0.091 ± 0.012
	U0126	0.204 ± 0.011	13	ns	0.9996	1.02	0.004 ± 0.014
	U0126 + serum	0.230 ± 0.012	12	ns	0.2652	1.15	0.030 ± 0.016
	U0126 + FGF4	0.214 ± 0.019	7	ns	0.957	1.07	0.014 ± 0.021
	DMSO + serum	0.271 ± 0.010	18	****	< 0.0001	1.36	0.071 ± 0.013
	DMSO + FGF4	0.287 ± 0.025	6	***	0.0002	1.44	0.087 ± 0.026
rERK2-LOC	Baseline	0.064 ± 0.009	12
	serum	0.480 ± 0.007	7	****	< 0.0001	7.50	0.416 ± 0.041	5.70
	FGF4	0.508 ± 0.008	16	****	< 0.0001	7.94	0.444 ± 0.040	4.88
	U0126	0.083 ± 0.011	15	ns	0.9952	1.30	0.019 ± 0.016	4.75
	U0126 + serum	0.082 ± 0.012	6	ns	0.9994	1.28	0.018 ± 0.014	0.60
	U0126 + FGF4	0.112 ± 0.019	11	ns	0.7481	1.75	0.048 ± 0.013	3.43
	DMSO + serum	0.353 ± 0.010	7	****	< 0.0001	5.52	0.289 ± 0.058	4.07
	DMSO + FGF4	0.358 ± 0.025	18	****	< 0.0001	5.60	0.294 ± 0.026	3.38

Statistical significance for differences among overexpressed eGFP-rERK2, endogenous ERK1/2 and rERK2-LOC was tested by one-way ANOVA and Dunnett’s test, accepting p ≤ 0.05 as significant. The ratio between Δ$\overline{CI}$ of endogenous ERK1/2 and rERK2-LOC shows the differences in magnitude order in function of the treatment. Symbols: $\overline{CI}$, average of CI values ± SEM; Δ$\overline{CI}$, difference between means compared to baseline value as reference; SEM, Standard Error of Mean; n, number of cells analyzed; S: statistically significant; ns, p > 0.05;

*, p ≤ 0.05;

**, p ≤ 0.01;

***, p ≤ 0.001;

****, p ≤ 0.0001.