Through measuring the mRNA levels of immune (TLR4, TLR7, TNF-α, IL10, NCF4, and LITAF), antioxidant (ATOX1, GST, and OXSR1), and erythritol-related (TKT, RPIA, and AMPD1) genes, we examined the changes in the immune, redox, and erythritol metabolic state in postparturient endometritis-affected Holstein dairy cows compared with healthy ones. The gene discussed is TLR7; the disease is endometritis.