Expression of full-length and mutant G-CSFR proteins in transfected WEHI-3B D⁺ cells. Full-length and mutant G-CSFR protein expression in vector-transfected cells (D⁺V), full-length G-CSFR–transfected cells (D⁺GR95), and truncated G-CSFR–transfected cells (D⁺GR-A, D⁺GR-B, D⁺GR-C, D⁺GR-D, D⁺GR-E, and D⁺GR-F) were detected by Western blotting using rabbit polyclonal antibody against the murine G-CSFR extracellular domain.