Table 1. A summary of the 8 models, showing the models with negative regulatory effects.

Negative Regulatory Effect	Model Number
	1	2	3	4	5	6	7	8
R-Smad Dephosphorylation	+	+	-	-	+	+	+	+
Receptor Degradation	-	+	+	-	+	-	-	-
P-Smad Degradation	-	-	-	+	+	+	+	+
Endogenous Synthesis and Degradation of R-Smad	-	-	-	-	-	-	+	+
PPM1A Stabilization	-	-	-	-	-	-	-	+
Which dataset caused rejection of the model:	pS	T1R	pS	pS	tS	tS	pS	None

The + sign indicates that a negative regulatory effect is included in a model, and - indicates a negative regulatory effect is NOT included.

pS: phospho-R-Smad time series.

T1R: type I receptor time series.

tS: total R-Smad time series.