AP3B1 and pemphigus foliaceus: The fibrosis-related markers (TGFB1, ACTA2, SNAIL, and TWIST) showed no differences between HPS2-AOs and cHPS2-AOs (Figure 2C), consistent with the findings of the animal study in that the Ap3b1 mutant (Pearl) mice did not develop PF spontaneously (Young et al., 2007).