Another study observed cytokine concentrations in purulent drainage obtained from HS lesions and found that, overall, pro-inflammatory cytokines such as TNF-α, IL-1β, IL-1α, and IL-17 were increased in addition to elevations in anti-inflammatory cytokines IL-10 and IL-1ra, although each patient exhibited a unique cytokine profile. Here, IL17A is linked to histiocytic sarcoma.