Human ROR1, also known as receptor tyrosine kinase-like orphan receptor 1, neurotrophic tyrosine kinase, and receptor-related 1 (NTRKR1), GenBank Accession No. NM_005012, a.a 24-403, with C-terminal Avi-TagTM fused to the Fc portion of Human IgG1 and expressed in a HEK293 cell expression system. MW = 71 kDa. This protein runs at a higher apparent M.W. by SDS-PAGE due to glycosylation.