The feeding of arthritic mice with food-based Lactococcus engineered to express CFA/I fimbriae prevents arthritis by inducing CD39+ Tregs to secrete TGF-β and IL-10 and thus inhibit TNF-α production and neutrophil influx into the joints (Maddaloni et al., 2015). This evidence concerns the gene ENTPD1 and Arthritis.