IL5RA CELL SURFACE MARKERS

The present invention provides cellular tags including an extracellular region, a transmembrane region, and an optional intracellular region. The extracellular region comprises an IL5 receptor alpha (IL5Ra) sequence linked to a transmembrane domain, and the recombinant polypeptide cannot function in signal transduction. The cellular tags can be operably linked to transgenes. The expression of the cellular tag allows identification, detection, selection, and ablation of cells expressing the transgene and the cellular tag. In some embodiments the genetically modified host cell comprises a transgene comprising a polynucleotide coding for a chimeric antigen receptor comprising a ligand binding domain, and a polynucleotide coding for a cellular tag. Pharmaceutical formulations produced by the method, and methods of using the same, are also described.