Transcriptional regulation is the set of molecular processes that determines the timing, cellular location, and rate at which defined genomic loci are transcribed into RNA. It operates through interactions among cis-regulatory DNA elements, including promoters, enhancers, silencers, and insulators; sequence-specific transcription factors; RNA polymerase and its general transcription machinery; cofactors; and the local chromatin environment ^[1][2]. Regulatory inputs influence the recruitment, assembly, activation, pausing, productive elongation, and termination behavior of RNA polymerase at individual transcription units. DNA accessibility, nucleosome positioning, histone modifications, DNA methylation, three-dimensional chromatin contacts, and regulatory non-coding RNAs contribute to the molecular state through which these inputs are integrated ^[2][3]. Within a gene regulatory network, transcriptional regulation comprises directed regulatory relationships in which transcriptional regulators modulate the transcriptional output of target genes, forming interconnected circuits that specify gene-expression programs ^[3].