RARB and lymphangioleiomyomatosis: As patients with LAM disease are treated with rapamycin, and rapamycin is known to downregulate RARβ, RARβ protein expression levels were quantified in patient derived angiomyolipoma and LAM lung cell lines after 10 nM rapamycin treatment in the presence or absence of 2 μM RA (Figures 2D–G).