Histological analysis and measurement of HMB45 staining in the lung tissue sections demonstrated that the LAM interstitial septum was significantly thicker in patients with LAM left untreated than in those treated with sirolimus (Figure 3b) and that the LAM cystic area was not changed significantly (Figure 3c), suggesting that sirolimus treatment prevents interstitial LAM septal remodeling and thickening. Here, PMEL is linked to lymphangioleiomyomatosis.