In white matter, asthma moderated the influence of IL-6 on dMRI metrics such that in asthma, higher IL-6 concentrations were associated with higher values of NDI (Fig. 4A and B) and FA, as well as lower MD, RD, AD, ODI (Supplementary Fig. 4A–E), whereas this relationship was absent in the control group. This evidence concerns the gene IL6 and asthma.