Sebocyte inflammatory signaling, marked by increased expression of cytokines IL6, IL8, IL1B and lipid-metabolizing enzymes, such as 5-lipoxygenase (5LOX) or cyclooxygenase 2 (COX2 or PTGS2), was shown to be increased in acne (21, 57), however prominent immune and barrier differences were observed already in the healthy skin rich in SGs compared to that with less SGs (11, 58). This evidence concerns the gene PTGS2 and acne.