(4) The potential role of Ikaros in regulating GTPase signaling is unknown and, in general, the mechanisms that regulate transcription of Rab GTPase genes are not well studied; and (5) although Rab20 was suggested to act as an oncogene in various malignancies [79,80,82,94,95,96], its role in B-ALL is unknown. This evidence concerns the gene IKZF1 and acute lymphoblastic leukemia.