Enforced expression of Gfi-1 induces Id1 expression and suppresses Id2 and Id3 expression. DA-1 cells (A), EML cells (B), and 5FU-BMC (C) were transduced with MMP-Gfi-1 retrovirus or MMP control retrovirus. RNA was harvested from transduced cells and analyzed by real-time qRT-PCR in triplicates. All samples were normalized to GAPDH. *P < .05 in 2-sided t test. Three independent experiments were performed. (D) DA-1 and EML cells were transduced with MMP-Gfi-1 retrovirus or MMP control retrovirus. Whole-cell lysates were harvested from transduced cells and analyzed by Western blot with anti–Gfi-1, anti-Id1, anti-Id2, anti-Id3, or anti-actin antibodies. Three independent experiments were performed.