These results suggest that PML-RARA mediates ATRA-induced C/EBPbeta expression.     ///    "We further provide evidence that ATRA mediates a direct increase of C/EBPbeta, only in PML-RARA (promyelocytic leukemia-retinoic acid receptor alpha)-expressing cells. "    ///    "Taken together, C/EBPbeta is an ATRA-dependent PML-RARA target gene involved in ATRA-induced differentiation of APL cells.. "    ///    "In addition, transactivation experiments indicate that the PML-RARA fusion protein, but not PML-RARA mutants defective in transactivation, strongly transactivates the C/EBPbeta promoter. "