Signal joint T-cell receptor excision circle (sjTREC) levels over the course of 24 weeks. The number of sjTRECs/5 × 106 PBMC was measured, as described in materials and methods, at baseline, weeks 12 and 24 after initiation of rhGH therapy. Box-plots show the median and IQR, and whiskers represent the 10th–90th percentiles. Symbols are specific to each patient according to the key shown in Additional file 1. Randomisation into three groups performed at week 12 is represented by different colours. Group A (red) received placebo, group B (purple) received alternate day dosing of rhGH and group C (blue) received twice weekly dosing of rhGH.