K- Box plot showing distance from the polyadenylation site (PAS) to the transcription termination site (TTS) in RPB1-52R and RPB1-25R cells for 1958 genes encoding major isoforms. p value= 0.8 (Mann-Whitney U test) Box limits are the first and third quartiles, the band inside the box is the median. The ends of the whiskers extend the box by 1.5 times the interquartile range. 