Stratifying PC patients according to lung fibrosis-like changes, we found that moderate PC patients without fibrosis had higher levels of TGF-β than healthy subjects (Figure 6B, purple vs. black dots); however, moderate PC patients with fibrosis had a slight increase in TGF-β compared to healthy subjects (Figure 6B, pink vs. black dots). Here, TGFB1 is linked to pachyonychia congenita.