ROR1 and B-cell chronic lymphocytic leukemia: In chronic lymphocytic leukemia (CLL) and mantle cell lymphoma (MCL), for example, the majority of patient samples show aberrant expression of receptor tyrosine kinase-like orphan receptor 1 (ROR1) (Baskar et al., 2008; Barna et al., 2011), a receptor of beta-catenin-independent Wnt signaling (Fukuda et al., 2008).