The Whitlow/218 peptide is a commonly used linker that connects the variable heavy (VH) domain and variable light (VL) domain of single-chain variable fragments (scFvs) and chimeric antigen receptors (CARs) that utilize an extracellular domain scFv for target antigen recognition. The Whitlow/218 linker affords the scFv with enhanced resistance to proteolysis and aggregation.