Evidence of high CD38 expressing Treg have been reported for multiple myeloma and acute lymphoblastic leukemia, where the use of mAbs against CD38 (daratumumab, isatuximab, and MOR202, Table 1) is more than a promising therapeutic option to reestablish a functional immune surveillance (145–147, 189, 191, 192). This evidence concerns the gene CD38 and acute lymphoblastic leukemia.