ROR1

null ROR1, receptor tyrosine kinase-like orphan receptor 1, combines an extracellular immunoglobulin-like domain, a frizzled-like cysteine-rich domain, and a kringle domain with an intracellular kinase whose activity is weak or ligand-independent. During embryogenesis ROR1 orchestrates WNT5A-dependent cell migration and polarity, but expression is silenced in most adult tissues. It reappears prominently in chronic lymphocytic leukemia, mantle cell lymphoma, and various solid tumors, where it supports survival and epithelial-mesenchymal transition. This oncofetal pattern has made ROR1 one of the most actively pursued CAR-T and antibody targets in hematologic malignancies. Monoclonal antibodies such as the ADC zilovertamab vedotin have been developed against ROR1.