Forced expression of C/EBPα induces PU.1 expression in 32D cells expressing FLT3/ITD. The 32D/α-ER/FLT3/ITD cells were cultured in medium containing 1 μM estradiol for 48 hours. Total cellular RNA from 1 × 10⁷ cells was extracted 0, 8, 24, and 48 hours after incubation with estradiol. Ten micrograms of RNA from each sample was subjected to sequential Northern blotting with PU.1 and actin cDNA probe.