The mRNA expression levels of AML-1A, AML-1B, MIP-1α, and IL-3 in myeloma cell lines. The mRNA expression levels of AML-1A, AML-1B, MIP-1α, and IL-3 in myeloma cell lines expressing AML-1A or AML-1B. ARH-77 (A) and MM.1S (B) cell lines were stably transfected with AML-1A, AML-1B, or empty vector (EV), and the mRNA expression levels of MIP-1α and IL-3 were determined. Three independent ARH-77 single-cell clones (A) and 2 independent MM.1S single-cell clones (B) stably transfected with AML-1A or AML-1B were examined by RT-PCR analysis as described in “Materials and methods.” GAPDH was used as an internal control.