However, typical CIDP patients tended to have increased mir-21 expression levels although this difference did not reach statistical significance ( P = 0.0792). miRNA expression in PBMC and cytokine gene expression in skin samples were not different between the study groups, Therefore, we have presented all results in Supplementary Table S4 .
However, expression levels of miR-21 showed an increasing trend in CIDP patients. miR-21 is a well-characterized regulator of cytokines produced by B cells such as IL-10, IL-6, and TNF-α [ 21–23 ]. miR-21 has recently found to increase in white blood cells of patients with polyneuropathies when compared to healthy controls [ 50 ]. miR-21 is also a known inducer of IL-10 expression [ 51 ] i.e., found to be elevated in our CIDP patient cohort.