TE-TTS terminate transcription in a cell type-specific manner. (a) Cell type specificity value distributions are shown separately for TE-TTS (red) located within introns, 3′ UTRs and downstream of annotated TTS. Cell-type specificity values are also shown for canonical annotated TTS (yellow). (b) Rarefaction curves showing the average numbers (±SD) of TE-TTS (dark blue) and genes with at least one TE-TSS (light blue) detected when all possible combinations of 1–8 cell types are used. Observed curves are fitted with a logarithmic trend line.