91 repeat breeder cows (RBC) examined by endometrial cytology. Including cows with and without subclinical endometritis. Analysis of endometrial mRNA expression of pro-inflammatory factors and mucins. Differences in mRNA expression of PTGS2 and CXCL3 in RBC compared with healthy control heifers. Dys-regulation of MUC mRNA expression might contribute to subfertility.