Single nucleotide variants (SNPs) in the genes were discovered using PCR-DNA sequencing for immune (TLR4, TLR7, TNF-α, IL10, NCF4, and LITAF), antioxidant (ATOX1, GST, and OXSR1), and erythritol-related (TKT, RPIA, and AMPD1) genes found in resistant and endometritis-infected Holstein dairy cows. The gene discussed is NCF4; the disease is endometritis.