P. ovis infestation was associated with significantly increased transcription of several cytokines and genes related to skin pathology, including interleukin (IL)-4, IL-5 (in HF only), IL-6, IL-8, IL-10, IL-13, IFN-γ, loricrin (in HF only) and filaggrin (in HF only). The gene discussed is IFNG; the disease is hydrops fetalis.