Abstract: Provided are genetically engineered induced pluripotent stem cells (iPSCs) and derivative cells thereof expressing a polyethylene glycol (PEG) receptors and methods of using the same. Also provided are compositions, polypeptides, vectors, and methods of manufacturing.

Abstract: Provided are anti-idiotype antibodies that specifically recognize anti-ROR1 antibody moieties, in particular, anti-ROR1 antibody moieties present in recombinant receptors, including chimeric antigen receptors (CARs). The disclosure further relates to uses of anti-idiotype antibodies for specifically identifying and/or selecting cells expressing such recombinant receptors, such as anti-ROR1 CAR T cells. The disclosure further relates to uses of anti-idiotype antibodies for specifically blocking or activating such cells.

Abstract: Provided are receptor tyrosine kinase-like orphan receptor 1 (ROR1)-binding molecules, in particular, to human antibodies specific for ROR1, including antibody fragments. The present disclosure further relates to recombinant receptors, including chimeric antigen receptors (CARs) that contain such antibodies or fragments, and polynucleotides that encode the antibodies, antigen-binding fragments or receptors specific for ROR1. The disclosure further relates to genetically engineered cells, containing such ROR1-binding proteins and receptors, and related methods and uses thereof in adoptive cell therapy.