Previous studies suggest that the microRNA-29 (miR-29) is one of the known TGF-β1-associated microRNAs involved in PF because it can regulate the expression levels of extracellular matrix (ECM) proteins such as collagen1a1 (Col1a1) and collagen3a1 (Col3a1) (Xiao et al., 2012; Montgomery et al., 2014). Here, COL3A1 is linked to pemphigus foliaceus.