Effects of the expression of full-length and mutant G-CSFR on LGM-1 cell growth after treatment with 10 ng/mL of rhG-CSF. Untreated and G-CSF–treated cells were seeded at 5 × 10⁴cells/mL, and their cell densities were determined daily for 10 days. I, LGM V (vector-transfected cells); II, LGM GR95 (full-length G-CSFR–transfected cells); III-VIII, LGM GR-A, LGM GR-B, LGM GR-C, LGM GR-D, LGM GR-E, and LGM GR-F (truncated G-CSFR–transfected cells).