Tissue processing.
Snap-frozen skin-punch biopsies were weighed and submerged in the necessary volume of TRIzol according to the manufacturer’s protocol (Thermo Fisher Scientific). The tissue was then disrupted and homogenized in a Qiagen Tissue PowerLyzer at 3,500 rpm for 30 seconds. Disruption and homogenization was repeated after a 1-minute cool down. RNA was extracted from the aqueous phase, while the interphase and organic phase were preserved for DNA and protein extraction, respectively. Biopsy specimens from 4 of the 28 enrolled participants were processed in a previous batch, in which the interphase and organic phase were not preserved.