Antisense transcription of the c-myc gene is reported for human HeLa cells, Burkitt lymphoma BL-60 t(8;22) cells, and diploid fibroblasts. The primer extension technique has revealed two start points of antisense transcription located within the first (untranslated) exon of the c-myc gene. The antisense nucleotide sequence of the first c-myc intron is similar to the DNA fragment from SV40 possessing binding sites for transcription factors GT-I, GT-II, TC-I, and TC-II. A DNA fragment of the first c-myc intron is able to form complexes with proteins of the HeLa cell extract at three nucleotide sequences (TTTCTG, TTTTTA and TGAGTTGTC). We suppose that antisense transcription is involved in regulation of the human c-myc gene expression.