Further studies have found that in cases with scrub typhus and HPS, the levels of TNF-α, IFN-γ, and IL-10 were significantly reduced within 24 h after treatment with doxycycline, while the levels IL-1β, IFN-γ, and IL-10 mRNAs showed a decrease after 2–7 days of treatment; hence, the mechanism of rapid fever reduction after doxycycline treatment was consistent with the decreased of the inflammatory factors [21]. This evidence concerns the gene IFNG and Hermansky-Pudlak syndrome.