Profiling transcription—a SLAM dunk Identification of the direct target genes of transcription factors could shed light on how healthy cells become malignant. Muhar et al. applied a modified version of a transcript-mapping method called SLAM-seq to identify the target genes of two transcriptional regulators of major interest in cancer research (see the Perspective by Sabò and Amati). The MYC oncoprotein selectively activates transcription of just a few genes, primarily those involved in basic cell metabolism. In contrast, BRD4, a bromodomain-containing protein that is being targeted for cancer therapy, activates transcription of many genes. Science , this issue p. 800 ; see also p. 713