In view of two early onset cancers in a proband with FHC we wondered whether SLC29A3 might predispose to neoplasia (e.g. by altering adenosine metabolism as extracellular adenosine has been reported to induce apoptosis and proliferation in gastric, leukaemia and hepatic cancer cell lines [17]–[20]). Here, SLC29A3 is linked to leukemia.