Serum levels of IGF-I adjusted for age and centre were not significantly different between cases and controls (means: 248.7 vs 244.4 ng ml−1, P=0.15), nor for the subgroups subjects with cancer diagnosis before or at the age of 55 years (272.0 vs 270.7; P=0.79), or after (224.0 vs 217.5; P=0.08). This evidence concerns the gene IGF1 and cancer.