In particular, the reduction of insulin levels would first of all inhibit the activity of IGF- 1, blocking a series of events involved in the pathogenesis of acne, such as hyperproliferation of keratinocytes in the pilosebaceous ducts, androgen-mediated hyperproduction of sebum, altered desquamation of the follicular epithelium, and proliferation of Propionibacterium acnes in the stratum corneum [66, 67]. This evidence concerns the gene INS and acne.