LDLR and pemphigus foliaceus: To find which lipid parameter is regulated by LDLR reduction and associated with PF, the levels of LDL, high‐density lipoprotein (HDL) and total cholesterol (TC) and triglyceride (TG) levels were analyzed in the plasma of 185 SSc‐PF patients, 55 IPF patients and 1642 controls.