TNF and acne: Several studies indicate that estrogens have anti-inflammatory roles in acne events; in particular, 17β-Estradiol inhibits interferon-γ in human keratinocytes [53]; and estrogens block proinflammatory cytokines (IL-1, IL-6, and TNF-α) and NF-κB [54,55], and repress macrophage activation and monocyte recruitment in inflammatory occasions [56,57,58].