RT-PCR analysis of the GMRβ_C chain between nucleotides 1281 and 1620 of the published sequence17 using RNA from hematopoietic cell lines (TF-1 and U937) and leukemic blasts of 2 patients with AML (Pt). L, ladder. Primers 1 and 2 were used (Table 1), and the expected fragment size was 339 bp.