IL6 and acne: In order to choose a sebum lipid for our studies, which has bio-active properties that may be linked to pathological conditions such as acne, we performed ELISA measurements using supernatants from SZ95 sebocytes treated with sebum lipids such as PA, linoleic acid (LA), oleic acid (OA) and arachidonic acid (AA), which revealed that only PA was a potent inducer of IL6 secretion, a marker for acne-associated sebocyte inflammation (21) (Supplementary Figure 1).