Transcript tiling array data from erythroid precursor cells. Results from 1 representative experiment are presented. (A) Transcript signal from the MYB genomic region shows very clear activity in exons and demonstrates that the array design and methodology are robust, given that MYB is highly expressed in the cells used. Occasional strong intronic signals were not coincident with spliced or unspliced ESTs and may therefore represent uncharacterized control elements or ncRNA. (B) Transcript data including HBS1L, MYB, and the intergenic region. The HbF-associated HMIP blocks 1 and 2 cover a region of high transcriptional activity. Again, there is no evidence of either spliced or unspliced ESTs. Given their magnitude in relation to the MYB signals and their complete consistency between different cultures tested, the intergenic signals are likely to represent important regulatory sequences.