IL1A and acne: C. acnes, a predominant bacterium in hair follicles, is a factor in acne vulgaris and inflammation that triggers proinflammatory cytokines, such as IL-8, IL-12, IL-1α, IL-1β, and TNF-α, in human keratinocytes, sebocytes, and microphages through toll-like receptor-2 (TLR-2), which induces the NF-κB pathway.