“…Furthermore, some Burkitt's lymphoma cell lines that have deregulated c-myc gene expression also have a concentration of mutations in the first exon and intron that correlate with abrogation of the transcriptional block (8). Similar intragenic transcriptional blocks have been observed in the human histone H3.3 gene (46), the human immunoglobulin ,u heavy-chain gene (19,35), the murine c-myc gene (40), the murine c-myb gene (2), the hamster c-fos gene (17), the Drosophila hsp70 gene (21), the simian virus 40 late region (23,24,25,42), the adenovirus major late transcription unit (16,18,33,39,41), and the human immunodeficiency virus type 1 long terminal repeat (31). Modulation of transcription elongation and termination is therefore a general mechanism for the regulation of gene expression in eucaryotic organisms.…”