NT5E and mastitis: Since our group previously observed the Ent expression system is commonly present in mastitis-causing E. coli (36) and the role of LCN2 includes sequestration of bacterial Ent, this observation in the target species raises a subsequent question: How is the host's immune response, i.e., chemokines produced by boMECs, PMN migration, and activation, affected in the presence and absence of bacteria producing Ent?