RAC1 and B-cell chronic lymphocytic leukemia: Yu et al. [31] found that in chronic lymphocytic leukemia, Wnt5a, a classical gene for noncanonical Wnt signaling, recruited guanine exchange factors by binding to tyrosine kinase-like orphan receptors (ROR1 and ROR2); the gene promoted tumor cell proliferation and metastasis by activating Rac1 and RhoA.