Table 3.

Contributions of endocrine and local IGF1 to growth

	Endocrine (E) activity, ″units″	Local (L) activity, ″units″	Relative weight, % of normal
2X	2	2	70
1XL	2	1	61
1X	1	1	54
LIP	2	0	50
NULL	0	0	34
Calculations:
E=(LIP-NULL)/2=(50−34)/2 = 8		L = 1XL−LIP = 61−50 = 11
E = 1XL−1X = 61−54 = 7		L=(2X−LIP)/2=(70−50)/2 = 10
		L = 2X−1XL = 70−61 = 9
Average E = 7.5 (43%)		Average L = 10 (57%)

The relative contributions of endocrine and local IGF1 activities were calculated on the basis of relative weight data (see Fig. 3C), considering the dosage (relative ″units″) and the sites of expression of functional alleles in the mice that are compared.