Higher levels of CD39+ T cells are associated with an overactivation of immunoregulatory functions of Tregs in SCD patients: in particular, the overexpression of CD39 leads to an increase in the production of adenosine and a decrease in the immune activation of T lymphocytes (Young et al., 2014; Allard et al., 2017). This evidence concerns the gene ENTPD1 and Schnyder corneal dystrophy.