Context: Recent developments in the IGF field have raised questions whether this is the right time to redefine IGF deficiency.

Objective: In this controversy, arguments are made against the need for redefining IGF deficiency at this moment, but rather to wait for further clinical developments.

Case: While a number of rare case-reports of IGF-deficiency with a precise molecular etiologies have been described, the vast majority of the cases remain clinically defined and without a genetic diagnosis.

Interventions: As IGF products are now available for clinical use in IGF-deficient-patients, we are still using GH-stimulation and static IGF levels as our only clinical diagnostic and classification tools.

Positions: We need to develop additional clinical tools, side by side with molecular tools for the diagnosis and sub-classification of IGF-deficiency. Chief among these are the IGF-generation test for identification of GH-insensitive patients and genetic panels of polymorphic changes in relevant genes.

Conclusions: until further progress is made in the clinical classification of IGF deficiency we should not change the current classification and when we do, it should be the responsibilities of the relevant societies in the field to conduct a consensus statement on the topic first.