Moreover, the key cytokines of the aforementioned type of reaction include interferon-gamma (IFN-γ), tumor necrosis factor α, interleukin 2 (IL-2), and IL-6, all of which are related to lupus erythematosus, lichen planus, maculopapular, morbilliform, vesicular rash, and erythema multiforme [56]. This evidence concerns the gene IL2 and lichen planus.