Cilluffo G, et al. - Herein, researchers applied mediation analysis (MA) to determine pulmonary function tests (PFTs) in Growth Hormone Deficiency (GHD) pre-pubertal children with respect to Controls, both before starting Growth Hormone Therapy (GHT) (T0) and after 1-year GHT (T1). The purpose of applying MA was to evaluate the extent to which the link between GHD and PFTs could be ascribed to a height-mediated (indirect) or a GH direct effect. Findings revealed impaired lung function in pre-pubertal children with GHD. This impairment was not exclusively attributable to the indirect (height-mediated) impact, but also to the direct GH action which was mitigated after 1-year of GHT.